Well my Zerg's knobbly ringa ding ding in my experince playing in the "Official SC2" beta I havnt experinced any bugs personally. Maybe I have a great PC who knows. Kaboose ill even invite you over for a Kom Kyk if you want.
Ive had multiple matches against easy AI, Strangers and one colleague that is also in the the beta and we havnt had an issue. Maybe we are just lucky maybe I havnt played a enough or perhaps my eye isnt critical enough but in Beta standards that I have taken part in its damn polished.
Perhaps I havnt picked up game dynamic bugs the but with regard to crashes, slowdowns, lag, gfx glitches, menus and general running of the game etc I feel its pretty smooth.