No one has a Tachyon yet (except protos). When it does come out, it will no doubt have that Microtech quality. In all likelihood you can't go wrong with either of those two brands.
The best in what way, artisticly or for manipulation? Older Benchmade customs, the 49 SPL (is anyone really going to "reef" on this one), the Benchmade 42, maybe the Tachyon, or some say the BM 45 in stainless was the best; again though, best for what?