I thought I would weigh in on this. The original Parsifal has gone through three upgrades. The first was a tweeter upgrade, spike change and some changes to crossover, this garnered the "Encore" addition to the name. Later Verity changed the tweeter again but felt that it did not require a name change as the change was small. Then in early 2005 they came out with the "Ovation" model. A larger woofer base, woofer change, tweeter, crossover were also changed. They also added an aluminum divider between the top and bottom to better control resonance. The Parsifal can be upgraded to the most recent Encore but not to the full Ovation. That being said, I have heard both in my system. I did get the aluminum divider ( an nice but not inexpensive change ), it helped to lock in instruments. The ovation may have a slightly better defined bass, not sure but maybe. I could tell not difference in the highs in my system. The Mids are the same, same driver etc. I did try some stillpoints Ultras under my Encores and they improved bass clarity and control significantly. I would take a most recent upgrade Encore with the aluminum divider and Ultra SS feet over an Ovation any day. But, I never had a chance to use the still points on the ovation so that would limit the comparison.
Now, to upgrade an original Parsifal or not. I am going to keep my speakers for another 5-10 years. So sending them back to Verity for driver checks, cap replacement and complete make over would give me a new set of speakers more or less, having the upgrade done at that time would be very worthwhile. I think we are way to eager to fall into the planned obsolescence trap.