Personally I despise motion compensation for 24p content. Better to just live with the judder on pans IMO. I've never owned a display which did interpolation in a livable way, and I've had just about every brand of display.
Plasma shouldn't flicker since it's driven at 600 subfields per second. This will be imperceptible for almost everyone and is far preferable to sample-and-hold. Phosphor lag on the other hand, is perceptible but the severity varied by plasma brand and year.
Yea phosphor lag was my main beef with plasma. It was very noticeable when I first got it but went away over time. Not sure if got better as the TV aged or my eyes adjusted. Either way it's a non-issue now. I believe phosphor lag did improve with later models. Is that right?