I've just finished episode 4. I was about to give up after episode 1 (even though I have loved all the previous series) but I pushed on through and am finding it better as it goes on, so worth persevering if you can.
Casting-wise - Imelda Staunton good, voice and mannerisms are excellent and well studied (although IS styled little too "old" for 1990s Queen imo). Quite like Princess Margaret casting. Initially thought Princess Anne awful but actually much better in later episode, particularly the scene where she puts her foot down with the Queen, I thought very much more authentic. Diana - voice and accent good, although much too tall and thin and too ott on the "Diana-isms".
But I'm so cross about the casting for Prince Philip, Prince Charles and the Queen Mother. Absolutely dire!!! Actually, if I cross my eyes I can see a vague physical facial similarity between Jonathon Pryce and (a much older) PP but his posture and voice and intonation are totally wrong and he looks way too old and doddery for 1990s Prince Philip. And who on earth thought the actress for the Queen Mum was acceptable?!!!!! Have they ever even looked at a photo of the QM?!?! Indefensible, diabolical lazy casting.
As for Dominic West, I'm actually raging... he looks NOTHING like Prince Charles and appears to make NO effort to capture his voice or mannerisms. Wrong wrong wrong! I have actually met DW a few times (lives locally) and I'd almost go as far as to say his normal voice is actually more posh than the one he is using for PC 🤣.
Some of the writing is really poor too, using clumpy dialogue to "explain" to us thicko viewers what is going on or things we might have missed during the time jump. Cringey, cringey, out of character unrealistic scenes too (see Prince Philip consoling Penny Knatchbull and late night telephone call between Queen and Princess Margaret to name just two).
Anyway enough ranting. I'm enjoying it well enough, although not a patch on the earlier series (Claire Foy/Matt Smith were just incredible).