. . .I actually like Jolene Blalock's portrayal of T'Pol. When I read on this board somewhere that Blalock is an "air head," I looked up one of her talk show appearances on youtube. That's not the personality I was expecting! So to me, she must have some talent since she was able to pull off a completely different persona with T'Pol. . .
In the DVD series collection special features, Connor Trinneer says she has the hardest job in the show, due to the character. Her blooper reel clips show how much she focuses on maintaining T'Pol, and when she does blow a line or react to someone's clowning (often Bakula), it's a complete turnaround from T'Pol's personality. I've done stage work (not professionally), and it's obvious she did work hard at keeping the persona. But sometimes someone goofing around off camera could throw her off, or some of John Billingsley's weird Phlox vocalizations could reduce her to laughter.