I've played on concert tubas that play better than the Dynasty tuba I marched with, but when I consider all things for the total package....i.e. durability (which in my experience with the tubas, was very good), ergonomics of the horn in my hands in carry and in playing position, as well as its "wow" factor in size...(its a big friggin horn, biggest marching tuba currently produced I believe)....I had no real beef with it.
However, my understanding is that the Dynasty tuba is the best instrument in the Dynasty line, which could help explain why I don't see what all the fuss is about with Dynasty.
Regardless....no matter the opinion of the majority about Dynasty, I'd say its pretty obvious that the man behind the gun can make a big difference in the end!