Not sure what you mean by animated Zach but both rule with mic in hand. Dios an origional but Im pretty sure Allens stuff is more demanding, more use of range and other variants. I also dont mean to imply in any way that Russell is a Dio clone, or of Walsh for that matter, its only once in awhile that I hear similar phrasing and tone. Allens voice changes alot in between as well, part of the reason why I feel hes one of the best vocalists in current metal... not that SX is current to the extreme or "new". They maintain enough old school influence to keep my interest.
see now, theres more CD's I need to catch up on... anything Dio, including the first Rainbow album, probably been 30 years since I heard anything from that besides Man on the Silver Mountain. Real partial to Holy Diver as well.
As far as new Symphony X release, I'd give them at least two years if not three with all this touring. Maybe that has inspired them though and ideas are already brewing.