Plinius 9100 and 9200?

Are there significant differences between these two amps?
For that matter, what about the 8100, 8200, and 8200 mkII? Are these all just successive versions with steady improvements? Are the differences substantial?
I owned the 9200 and from my research the line in general is known for a somewhat warmish and laid back sound. The 9200 had a refinement and slight shimmer on the top end. I would characterize it as a very smooth integrated lacking in grain or glare.
I haver owned the 8200 and 8200MKII at the same time (only for comparison). We compared these at length. The 8200 is more vibrant and defined. It has an energy to it. Musical in an exciting kind of way. The MKII sounds slower and more laid back but seems have a wider stage. Hard to say. A friend of mine and I liked the 8200 better. These findings were confirmed in conversations witha plinius tech. Audio has many reviews and these.
Did you listen to vinyl at all while you had them both??

You also haven't mentioned what speakers you were using when you compared them??

From what I understand, Plinius made quite a lot of changes (i.e. improvements) to the phono stage when the 8200 MKII arrived, so I'd be interested to know if your comparison was CD's only??

I know I'm awfully happy with the 8200 MKII, and I never, ever think about more focus, speed, decay, soundstage or anything like that while listening to music through that sucker.

It is great. 'Nuff said.
Thanks for the responses. So is it safe to say that from the 8100 to the 9200 this is essentially the same amp with incremental improvements in each one but no earth-shattering improvements from model to model?

I think you're looking for differences between these:

A. 8100/9100

B. 8200/8200MKII/9200

A has less power and no phono stage...

B has manly-man power and a phono stage!

So they are different, but I would imagine there's a Plinius "house sound" in them...
Thanks, now I understand. I think I should be looking in the B range.
The comparison was CD only. They are both great units so one could go either way depending on ones tastes.