I've been looking for a new trombone lately, and I was wondering about your input on certain models...
I've heard a lot about the King 2b, particularly the Silversonic? What is your input on it?
I hear that the Conn 4h and 6h are comparable to the King 2b and 3b. How do they measure up to each other?
What's the difference between regular King 2bs and the Silver Sonics?
What's the difference between the 2b and 3b, anyhow?
Are the modernly manufactured King 2bs/3bs as good as the vintage ones?
What are your personal favorite jazz trombones that you would recommend?
It would be greatly appreciated if you could answer any of my questions

I use a Shires, but those are very expensive.

Lots of pros use the Bach 12's and 16's. I would check those out. If you can find a used one from the 60's or 70's, you're golden.

One of the guys that I play jazz with a lot is very positive about the Conn 6H.

The difference between a 2B and a 3B is the bore size. The 3b is a slightly bigger horn.
There are those who say modern Kings aren't as good as the old ones. Personally, I think if you look for a good one you'll be fine. However, some players agree that of the new 2Bs and 3B's, if you really want the projection, go for the sterling silver bell.
Keep in mind , a silver sonic (aka SGX) is different. The SGX (and please correct me if I am wrong) is a silver plated bell outside, with a gold wash on the inside. The sterling silver bell is solid sterling with no gold wash. I'm not here to tell you which is better, just that they are different.
I play a 3B with a sterling silver bell circa 2004. It's a fantastic sounding horn, great slide, huge sound, plenty of bite when you need it. The tuning is a little quirky, I will admit. But it's nothing I haven't been able to work around. As a matter of fact, as long as I play it regularly, I don't even have to think about it.
I also took a Bach 16 on the road with me last year and liked it quite a bit.
At the end of the day, the best horn is the one you like the best. Good luck in your search.

I've heard amazing things about Rath horns for jazz, but I don't know much about them... Edwards makes nice custom jazz horns, and my buddy who is all about lead bone jazz playing just bought a yamaha jazz horn. He liked the yamaha way way better than the other 6 he tried, including bach's, kings, and conn's. It all comes down to what you think plays the best for you!

I have a King 2b from 1945 which is considered one of the best jazz horns ever made. I play a Bach 42 all the time though because I like the slide much more. I'm going to start looking for a Bach jazz horn just to see how the slide works. Also please remember that the horn doesn't make the player. I know kids who go out and get 1500$ horns and its unnecessary. Become a good player and then find out which horn fits you more.

I hope you're not using the Bach 42 for lead parts in jazz. It would be like trying to drive a tank in the Daytona 500.

Why? You know that many of the top professional jazz trombonists are starting to use large bore horns now, right? (I have reason to say so after performing with Robin Eubanks last year, who used a large bore Yamaha Xeno and a 4g mouthpiece.) I know many people who use a 42 for lead bone playing, including myself when I have to. Actually in today's typical big band setting, almost all of the 2nd and 3rd bone players use large bore horns. This can create a problem when the lead bone player is on a small horn because often he/she can tend to get covered up by the bigger/fuller/louder horns. I don't necessarily agree with large bore horns being used for lead bone playing, but I wouldn't compare it to driving a tank in the Daytona 500.

Sure, there are guys out there like Robin Eubanks that can make it work. Some big bands (Like Dave Holland's Big Band) use all large horns. Others, like Gordon Goodwin's group all play 2Bs. It's a matter of blend. If you play lead on a 42 when the rest of the section is on small horns, it just won't blend. Personally, just about every group I've played with has used small horns. I would venture to say that the big horn bone sections are still more the exception these days. What you play is your decision, but you really should respect the section you're in. If you're the newcomer, you should work to blend with them. Ideally, in a perfect world, we'd all own a large and a small tenor, and a bass, and maybe even an alto. Then you're set for any occasion. But I realize that's not terribly realistic. If you're primarily doing big band and owning multiple horns isn't an option, I'd really recommend something along the 3B or any other .500-.508 bore horn. But that's just my humble opinion.

This can create a problem when the lead bone player is on a small horn because often he/she can tend to get covered up by the bigger/fuller/louder horns.

This is a common misconception. The sound of the smaller horns are usually brighter and narrower, so they will cut through the texture. Thus, they will be heard more easily. Jay Friedman even said this in an article that he wrote. Of course, for blending purposes, he uses a large horn. But he said if he wanted his sound to cut through to be heard more easily, he would use a small bore horn.

So, is there a sound difference between the silver King trombones with gold wash on the inside and those without?

I believe so. Your ears may not notice the difference. Play both and decide for yourself. Have a more experienced player with you if possible for an outside opinion.

I've found a dealer who's selling a King 3b silversonic for $1300. Playing lead trombone, is the 2b considered much better than the 3b? and, he gave me a big description about how he did lots of work on it, including:
-Replaced neckpipe, put in new tuning slide
-Put in a gold wash
-Bought a new slide
-Installed a new lead pipe (Shires 0.525)
-(Minimally) buffed and lacquered entire horn
-Cryogenic freezing to release bracing stress
PS this is an F trigger

What do you think? Has this been altered to the point that it is no longer a king 3b? and how much do you think i could re sell it for if unsatisfied?

The 2B is just a smaller horn (Ithink a .490 or .500 bore), and generally helps with ease and projection in the upper register. If you are used to playing a larger horn, you might feel the 2B a bit stuffy. If you want something a little bigger with a good amount carrying power, the 3B is great (.508 Bore).

Silver sonic-now called SGX--trombones have a solid sterling silver bell, and the older ones had 24K Gold plating on the inside of the bell. Some of the newer have a the gold-plated inner bell, as well as gold plated tuning slide and hand braces.

I myself am looking for a 3B+ Silver Sonic (SGX). The 3B+ has a .525 bore. and a 4B (.547 bore) Silver Sonorous with an F Attachment.

Essentially the Guy who added that shire lead pipe just made a dual-bore 3B. I think it's a good deal, but you should ask for the serial number and look up when it was manufactured. If it's a horn from the glory days (1960-1980) then I would say he made unnecessary changes to a great horn.

Actually, quite a few people for some strange reason find the 3B "stuffier" than the 2B. Maybe it's because the 2B is a dual bore slide and the 3B is not? Who knows. But I have played 2B's that felt more open than my 3B. But I still wouldn't part with it.
Also.. as far as King Horns.. a King 2103S is a solid sterling bell. A King 2103 SGX is the silversonic with the gold wash.