I effectively gained another gear. I did this mainly as a way to boost highway FE. I don't think it's going to have a big impact on city mpg. In fact, a case could be made that this could hurt city FE (at least that's what someone at teamswift said who did it. He said he stood on the gas much more to get the car moving, which negated the gains from different gearing... then again, I'm not likely to do adopt that driving style...)
Haven't decided what I'm going to do with the short legs. I could easily sell it - some of the teamswift speed enthusiasts like do do the exact opposite of what I just did: put the 1.0 trannys in the 4-cyl GT cars.
I'm tempted to just hang on to it because: I'll have a back-up in case I have trouble with the taller one (it's got about 180,000 km on it); or if I ever want to revert the car back to "stock" for some reason.