It bothers me that in all the latter appearances, Sirtis stopped playing Deanna Troi and just played Marina Sirtis.
Does it bother anyone else?
Or (since Troi was seemingly never too popular) was it an improvement?
I think this was an improvement. Her original greek-inspired accent sounded like a speech-impediment. It was the biggest problem I had with the character. She's much more charming with her regular UK accent.
Maybe it is not so obvious to over-seas English speakers but that isn't her regular accent, it seems to be a weird mix of RP and.. something...
When she does her appearances on voyager she is getting a lot closer to her normal accent* but not still not quite.
* which seems to have shifted over time because of living in the US.