Astarion sounds just mostly "posh" and theatrical to me.
As for accents. I don't mind them speaking with British Accents, but I'd prefer if they stuck to variants of English. I never liked the "put on" accents of "German Accent" and "French Accent". If they want that, at least get someone from those countries to act the part, and not "make it up", at least then it sounds more believable.
Mostly it sounds to me they use European actors, being an European company and all.
Seems to me it's mostly Americans who find it "off putting"? I guess to them it's something exotic, where as us Europeans are more used to British accents?
Could be. I'm American but my husband and I mostly watch British and Korean shows with the occasional German or Italian show thrown in. We don't care for most American TV.
Also, yes, good point. 100% I welcome all accents but from actors who can speak in them natively.