Zen beat Takemiya Masaki a few weeks ago in a non-blitz two-game match at five and four stones. It didn't even use an excessive amount of hardware, just a couple of boxes:
After the 25 is up, each player can make as many moves in 30 seconds as they'd like, the 5 means that they can overstep that bound 5 times (by 30 second increments).
http://gogameguru.com/zen-computer-go-program-beats-takemiya...