The DVI-only boards definitely have less lag, around 1/4 frame, and definitely less than a 1/2 frame.
I don't think the 30" korean monitors really caught on, there may be a thread on them somewhere, but i don't remember seeing one. The risks of buying overseas goes up a lot in the 30" pricerange. And don't be fooled by the seller Red_Cap's personal 1 year warranty, if there's a problem he'll just string you along till your paypal time window runs out.
I made a thread comparing them a while back. There are many models AND some of them are sRGB, with matte coating (very non intrusive compared with ag).
They go for around the same price as a used U3011/ zr30w