I just finished installing a Sirio .18 in my T-Maxx. It's already broken in, fired up w/ one pull, tuned it up...good temps, a little slow on throttle response still but it seems to run pretty good. The only thing is that my 2.5R would smoke this thing!! Way more low end, wheelied on any surface...the Sirio...nada... no wheelies!!! pulls hard after a softer start (slipper is almost locked) but doesn't seem to have alot of bottom end. The 2.5R still seemed faster. Maybe I've overlooked something or it needs a better tune...but if this is all it's got...I'm not impressed.