Although T1 Firewire offers a pretty unique feel, we have heard from some of our customers that it plays similar to cyclone...
I'm actually playing with both the T1 Firewire in one racquet and Cyclone in another (both Pure Storms @ 48#). I've had the T1 in for about 5 weeks and the Cyclone for a little over a week. I'll say that they do both play very similar, but T1 has about 10% more power and spin over Cyclone. The T1 is more crisp a a little more feel than Cyclone, IMO. I'm actually very surprised by the tension maintenance in the T1. The string felt super stiff and was a little nervous for my arm but it is actually reasonably comfortable. Probably more so than Tour Bite Soft.
The T1 is in a racquet I use for almost exclusively play tests and I keep wanting to cut it out for my next set up, but I'll pull it from the bag for a few sets and continue to be amazed at how good it still plays. I'll have to cut it out soon anyway since I just got another string I've got to review soon.
Glad I found this thread because I wasn't sure where to purchase the Tier One string. I'm going to buy the poly/multi set and will probably keep using this string until something better (for the price) comes along. This is seriously good stuff. I'm just not looking forward to stringing this going forward. It drew blood on more than one occassion and the string recoil was quite a pain.