I think the early MGW worked with Blowfish, but the current ones don't. I just had to take my Blowfish off a few days ago to make room for the MGW during a clutch swap ;P
I have the newest MGW that mounts to transmission. it works great. Solid shifts but I still lock out 3rd when I power shift at or above redline. Have to granny shift at 6500. Trying clutch line next to see if it helps. I would recommend it as it makes a huge difference in driving and racing.