Personally, I prefer the Glock 26... excellent size, very accurate, and very reliable. I've owned mine for a few months now and have made this my primary summer carry weapon of choice.
Last year I shoot the XD 9sc and S&W M&P 9c on the same day. At the time I did not purchase either because I could not shoot the Glock 26 at the time... later I did and purchased the Glock shortly after that.
You should shoot them both for yourself and find out which one you like best.