I've owned and shot a Glock 26 and a SIG P220. I still have the Glock, traded off the SIG. To be fair, the SIG was a police trade-in, so it had a LOT of wear and tear. One rather crucial part ended up breaking(the trigger reset spring), and after the factory fixed it, I traded it for a Charles Daly High-Power just to be safe.
I'm not a big fan of Beretta, I think they are a little high-priced for what they have to offer. Don't have any personal experience with them, though.
About the Glocks not being accurate, check out this link:
http://www.gun-tests.com/issues/20_8/features/Subcompact-ACPs-Glocks5627-1.html
I have the hard copy of this issue of Gun Tests, in which the Glock 30SF beat the $1300 Kimber SIS, and the $1000 Springfield Loaded Ultra Compact in several accuracy tests.
People use them to compete with in IPSC matches all the time.
Glocks are great,
SIGS are too,
You have to decide,
Which is best for YOU!