Does "light weight" mean weaker and easier to break [than the 5MT] under spirited use though? And would it bolt up to an EJ25?
Lightweight means it's not the hand built STi unit. It without a doubt is better than the 5MT in terms of strength. My guess is that it would bolt up the the Ej25, as the 2010-2012 Outback/Legacy had the 6-speed manual with the EJ, and now the FB engine with a 6-speed, and as far as I know, it's the same transmission.
And Dpm, is this actually the same one that is hooked up to the diesel engine? If so, then it probably would be a good choice to swap for a few WRX guys with 5-speeds.
Also, seeing as how the new FB and FA engines are very easy to turbocharge (even if they came N/A from the factory) I see aftermarket turbo set up getting more popular for N/A guys, and maybe even draw several people to buy the N/A with the 6-speed and turbo it....Hmmm....