Well, once you play with them, you may find other bios will work better. Of course, the MantraRay XT's may work great for you, too. It's a good starting point, but it's something you can't determine until you actually HAVE your sticks in the system and everything all set up. I probably tested over 20 different bios variants between D23 and D26. The Merlin bios, which everyone raved over, absolutely would NOT perform in my system. The MantaRays worked on my other system that was identical to my main one, but not on my main. I eventually got my best results with the D24's. One day I switched out ram and then switched it back after 10 minutes. The D24's were no longer stable at my speeds anymore. I did nothing but take a stick out, put a different stick in, then take that out and put my original stick in. But that's just the way these things go sometimes.
So, I ended up with the D26 Splitfire CPC-Off (don't recall which bpl table variant it was) to finally get back "up to speed," so to speak.
The biggest thing I'd look around these forums for is what voltage TCC5 likes to run at, as you and I have been PMing about voltmods and you don't want to fry your ram.