and their new content tries to ape modern Bioware sensibilities instead of maintaining the line of the source content.
This is key, yes. But Baldur's Gate 2 being what it is and Siege of Dragonspear being its own thing, hopefully, they won't go too overboard with modern BioWarian design.
Basic competence is there already, the art design is much better and bringing in those VAs shows they are trying. The ruleset is still the same and EPIC BATTLES aside, it shouldn't take much to make for interesting encounter design. All it would remain is for MCA's endorsement to hold grounds and SoD becomes a very solid experience that, unfortunately, requires you to play BG:EE with all the bad content that comes with it.
I can see why this wouldn't persuade you but I guess I'm just too much of an optmist.