Wow... I'm glad you asked me the question about the tuba solo, otherwise I would never have noticed this piece. I symphony for concert band/wind ensemble... I had the idea myself, but I don't have enough composing skills to back it up yet. My first symphony will probably be for concert band though... I am not fond of strings, I personally feel that a wind ensemble can express much more. Speaking of that tuba solo at the beginning, I don't think it is that necessary to write two staves for the tubas on page two, I've played tuba in band music where the tuba had a solo line and the section piped up underneath all on one staff, and with more stuff going on than what you have here, so writing too staves isn't entirely necessary, I would say you have the choice.
Your knowledge of instruments really shines here, if I didn't play clarinet, I would probably deem the parts impossible just looking at them. This work of yours shows that people who play the many instruments tend to write more challenging parts for them, while still considering them for playability. As a fellow multi-instrumentalist, I give you a high-five.
There was a small part where I thought it was losing focus, but I won't bother mentioning it since it was only an initial response and you picked up the interesting almost moments later. So good job on that, this piece did hold my interest. I would suggest featuring the oboes more in future movements, you haven't really given their section much of a spotlight yet like you have the other sections. In fact, I don't even remember hearing them anywhere. Mmmm.... I can't wait to hear the soprano sax.
Thank you for separating the horns and saxes, I see way too much wind music where the horns and saxes either share the same part, or the saxes get the interesting parts and the horns, though incapable, are given the boring parts. You showed a lot of balance between the sections, and that really separates the men from the boys.
OOoohhh..... alto flute. I'm liking this....
An agitato next? I would have expected something quite the opposite. Is that your intention?
Congrats on this wonderful piece of music so far, I can't wait to hear the follow-up movements.