I don't think there is much advantage from the different shoes as long as you can adjust them to fit in the correct position. As I have small hands with shortish fingers I find this a problem with Steyr LP50e. I have made my own "back to front" shoes with the clamp at the front and a thin blade shoe behind it, its very successfull on the LP50 and 50e which has a long reach. I'm currently making one for a club mate with an LP 10 who has the same problem. My preference, I think a flat or shallow curve are better as long as you can find the correct position consistantly, that's the advantage of a curved shoe but its just preferences, with rifle trigger technique its a bit different, the top coaching book has two pages on shoe shape!
Good shooting
Robin
Walther KK500 Alutec expert special - Barnard .223 "wilde" in a Walther KK500 Alutec stock, mmm...tasty!! - Keppeler 6 mmBR with Walther grip and wood! I may be a Walther-phile?