i agree with wannabee 100 percent. the dynoport cant be beaten so far. 

if you want a racey zingy sound - perhaps the very pretty lrd is a good choice if u want the hit and sound of a 2 stroke baller.

the ct pipe for the 500 is boring as all hell but it is the most modern of them all.  sometimes the best is just to boring....  im not sure about the 250 pipe at ct. perhaps a look there too!

***Edit 1***

I have plenty of videos of my dynoport pipe on my quad on youtube. They big volume pipe is a great pipe. Dynoport also makes a mid-top pipe. I am running a ftz pipe and silencer on my ice quad and let me tell you it's far from fuckin crumby dude. It pulls hard real hard. Paul turner mid pipe is an option fr moto. CT makes a pipe for lts. And the psi is a great pipe also comes on hard and quick. There is lots of things that need to be setup along with the pipe. Can't forget about lrd also. Another strong pipe basically the same as the dynoport big volume. Again so many variables go into the pipe/motor setup to make it work to its full potential. Fmf or the turner mid or psi may be good choices for moto but I like th dynoport big volume.

do you have a video of the dynoport on a stock or ported cylinder?  i have been saying that pipe rocks since the dyno image was released.