BiTurbo is th Dodge of pipes. Low cost and fast. You can spend more and get more durable, but the performance difference will be slight. I ran a test on my Tomos TTLX with 70 Airsal. I installed all 3 pipes and GPSed
Techno Bullet 46
Biturbo won by 1 mph. $65 The down side is that the resonator can on the end is riveted on, and tends to vibrate loose and eventually fall off. Keep an eye on it.
If you want the Ferrari of pipes, there are plenty of $200 awsome pipes out there for Tomos. Don't expect to pick up more than a couple of mph, but you will get beauty and durability for your extra coin.