Well Done! Wow John I thikn you really have something going on. I think that your symphony it's very good. It's a really "pleasure" to listen a work that is more con the classical-romantic mood, made me think of Beethoven in some harmonic constructions, and maybe (as other user said before) in Dvorak, in matters of "rhythm". The themes and ideas are very well presented and estructured, and you can mantain an almost (if no full) coherence in all the symphony. Even in the 2nd movement that you said it was based on a piano concerto, when I listened to it I could still feel the first movement going on. But (there's always a but) I thought too that the first mvt could have more counterpoint, more "moving" variations of the ideas. The 2nd mvt it's rather repetitive, you could have added another idea or section to complement, to carry more attention for then, present the main ideas again. And maybe use some of those new ideas in the wo next mvts, but still, I thought the 2nd mvt was great, better than the first. The 3rd movement I thought was the best, It's very energetic well constructed and it's the one that has the more "complex" development of the ideas I think. And the finale I love how you present the main ideas and the you go into that awesome and powerful final, but I think repeating the final of another mvt It's kind of... again, repetitive. And you could have done (and this speaking of all the sympony) a lot more developing of the main idea (the "really big tune").
Overall, original, wery well constructed (I couldn't make a structure like you lol), very energetic and coherent (no slope chords, notes or sections), pleasant and it's lovely how you include romantic and classical elements, I'm a little tired of new sounds and dissonant chords. I think you have very good ideas, but you could develop them much more and add more complex counterpoint and rhythmic stuff and more ground changes, with that, your music could improve a lot, I think you are good John. I miss the dynamics, I understand the MIDI problem I know it would sound great with the dynamics. Please when you can, upload scores.
Hope my english it's not so bad, and hope my review It's good, I liked your symphony;
Sebastian