Pros and cons of adding??

 

Pros
added HP
Better MPG
helps with throttle lag
adjust speedo for bigger tires
can monitor 4 functions
adjust shift points
remove speed limiter
can add custom tunes (Gryphon)
best $300 ever spent

Cons
None

 

I didn't see any MPG improvements, but some claim to. The throttle lag is the best part of it IMO. It's also nice to have a tach, since my STX doesn't have one. I use the stock towing tune, so I can't comment on any customizations or custom tunes.