I like them both, have 3x M57s and a Kimber Combat II 10mm. Like them all, FWIW.

The M57s are a bit more powerful, somewhat more accurate than my 10. I get about 1200 fps from 180 grain bullets in the 10; about 1300 w/ 215 gr hard cast bullets in the .41.

I hate an either/or choice; get both. In .41, I'd sure recommend a no-dash M57. I'm please w/ the Kimber 10; the Eclipse is a fine pistol also (have had a 4" .45 Eclipse for eight years now, and it's great). If pushed hard, I'd get the .41 first...