I was having trouble deciding between the Legion and S2 so I bought both, put all the CGW trigger parts in the S2 and put a greyguns trigger in the legion. Did one combined range session with both guns, then each got its own range session, then I followed up with another combined range session and came to the conclusion I like the way the Sig shoots and feels for me, part of this could be that I have really big hands and the S2 even with large grips still felt cramped getting on the trigger.
I really wanted to like the S2 better as its a really well made gun and I love hammer fired guns but when it came to shooting them the Legion just worked for me.
The only place I had a edge with the legion was with really tight shots(8" steel at 40yds) due to the nicer trigger and while I do that in practice regularly its not as common in a match.