Are you looking for an American or German sound? Do you prefer front vs. top action in piston horns? I've done a lot of playing on the horns listed below.
I own the new King 2341 - great american sound. Fit and finish could be better but nothing I can't live with for the price. Easy free blowing horn with good ergonomics for me with 4 front action valves. An excellent all around horn. Not to big - not to small. Can handle Community band work and quintets easily.
The VMI 3301 is comparable to the King in many ways although I thought the King had a somewhat broader bigger sound. The VMI is somewhat more expensive and I didn't like the ergonomics personally. It has a big valve set so if you have large hands you might like it.
The Miraphone 186 is a classic horn that never goes out of style and has great resale value. Probably the most consistent horn made has to how they play from one example to the next. The King on the other hand can vary greatly from one example to the next. The 186 has the classic German sound & more then able to handle Community band and small quintet work.
The MW25 I think of as a slightly bigger darker version of the 186. Some folks like them others don't. I think the 186 is a much nimbler horn. I played a MW25 through college and was okay with it although I preferred the sound of my Rudy Meinl (which I would recommend but is probably out of your price range). The Rudy while listed as a 4/4 horn is more of a 5/4.
The other horns on your list I have not played much. One horn not on your list but maybe worth considering - a Besson. When I had no money just out of College I bought a used top of the line Besson New Standard. This is a 3 top action valve compensating TUBA. Built like a tank in 1971. I didn't know much about Besson then or now but it seems that the quality has wavered back and forth from excellent to bad and back. Mine is the best fit and finish I have ever owned. Intonation is superb and the valves are excellent. I've owned the horn for 25 years. The sound is very nice and it makes an excellent Brass Band and Community Band instrument. With the compensating system you really don't need the forth valve. Some folks find the low end on these horns challenging although mine has an excellent bottom. These are not free blowing instruments but the notes slot solidly and effortlessly and my horn also has terrific top end. Personally, I don't like the top action valve hand placement and the ergonomics suck, but you can eliminate that with a stand.
Bottom line is these are available dirt cheap used and can be a solid all around horn --but-- are not the most popular or prettiest girl at the dance --but-- sometimes the most popular or prettiest isn't necessarily the "best" for you.
I like the King 2341, Conn 5J, & Conn 25J. I'm also searching for another horn & I've narrowed my search down to these 3. I'm leaning toward the 25J 'cause it's a top valve horn, but the money will be the main determining factor.
Put it this way: You can probably catch the Allora on sale, or get an open box/demo deal, or get hold of a cooperative sales person, or some combination of the above and get the thing for around $2500.
Which means: You will never lose more than $2500 on it no matter how long you keep it or how beat up it gets.
If we're talking percentage change in value, maybe the Miraphone might win. If we're talking actual cash money (the stuff that goes in your pocket), I'd place my bet on the Allora winning.
If you know what you are looking for, there is an occasional deal on eBay. I got my Besson BBb 3-valve comp for a total of $401 including shipping, and all I had to do to it, which was disclosed in the listing and good pictures, was put new springs and corks on the spit keys.
It is my fault I forgot it had the smaller receiver and I had to turn around and purchase a Denis Wick mouthpiece!
You should make an effort to get to the Army Tuba Conference in Arlington VA in January. You can try all of the tubas mentioned plus many more both new and used, and you can sometimes buy one on the spot if you feel inspired. Try the King and the big Jupiter. If $ is a constraint sometimes you can find used Jupiters for decent prices.
