I haven't played either of them, so I can't weight in with personal experience with them. If you haven't already, I would suggest calling the folks at Fiddlershop They will be very helpful in answering your questions and help you in choosing the violin you want. As I customer I can say that they aren't pushy at all, they just want you to be happy
World's Okayest Fiddler
Welcome @jamal_I72 - similar to @damfino above - I cannot compare - but - in saying that - I have had the FM Concert during my 3 years of playing ( plus another 3 fiddles just for FUNNNNN ! )
Just about 2 weeks back, I upgraded to a MZJ 905 from FiddlerShop - it is an awesome step forward for me.
Unless I have a "serious problem" with any one of my fiddles - I'll never let them go.... my plan is to keep my FM Concert ( real nice beginner/intermediate instrument - I have learned a LOT from playing it ) and to keep her steel-strung and use for alternative cross-tunings ( you know, like DDAD and so on ) for some fun old-time fiddle tunes...
But that's just me... ROFL
I've heard/read about the Soloist - and - it does sound a nice instrument I have to say, but I haven't much to compare it against the Ole Bull - so the ONLY reason I'm responding at all to your post is that "yes, there is NOTHING wrong with the Concert at all for where it is placed in its price range" - and sure - there are "better" to be found when you are aware that from your own point of view that "there is more to come"....
It is truly an awesome journey - good luck and best wishes with your final choice - and never hesitate to use the FiddlerShop "chat" to speak to Mike and / or Pierre about what you are looking for - these guys will assist, with no "sales pressure"...
I seriously recommend not copying my mistakes. D'oh -
Please make your own, different mistakes, and help us all learn :-)
I have a soloist, but they did not have the Ole Bull when I got mine. The soloist is a great violin, easy to play, good sound and exceptional build quality. I'm sure the Ole Bull is as well. Keep in mind that each violin, regardless of what it's called, has its own unique voice, so your question really isn't simple to answer. I'll bet if you ask them they can demo some for you on a video and then you can pick the one that sounds best to you. I can, however, assure you that whichever one you pick it will be a quality instrument.
A positive attitude may not solve all your problems, but it will annoy enough people to make it worth the effort. ~Herm Albright
The two instruments are not so far apart in quality or characteristics that anyone is likely to be able to say "This one is this way, and that one is that way." The individual variances within each line will be larger than the difference between the lines.
I like the dark, rich end of the tone spectrum, and after listening to a bunch of them in videos on Youtube, the average score (for sound) for each were neck and neck. You might score them differently, though.
That's the first thing I'd recommend you do. Get on Youtube and search for "fiddlershop soloist" and "fiddlershop ole bull". Pay attention to the dates, because they were having quality control issues and changed manufacturers about a year ago. So listen to ones that are from July 2016 on.
If one or the other clearly appeals to you more, that's what I'd recommend you go with. If not, ask Fiddlershop to do a comparison video for you.
If you've picked a model, but are concerned which specific one, have them play 2 or 3 for you, and pick from those. Tell them what characteristics you're looking for in a violin, and they'll try to find several that fit those.
If you're still concerned about which one you'll be happiest with, get more than one and ship back the ones that don't make the cut. That will cost you the cost of shipping, but it's not all that much if you're in the continental US - well worth the peace of mind.
When I stopped by the fiddlershop I was trying to decide between the Soloist and the Ole Bull. After playing half a dozen fiddles I ended up buying a Holstein Traditional Cannone. It definitely comes down to the individual instrument. If you let them know how much your planning to spend and the characteristics your looking for, I'm sure they can match you with the right fiddle.