Take it for what a newbie competition shooter has to say...
I've shot glocks for about 6 years for SD practice & classes, just got into competition (3 Gun and USPSA) this year and wanted to try the 19/2011 platform, so I picked up a Rock Island 2011 in .40. I flat out shoot that thing much better! It points perfectly, fits my hand better, and is just more fun to shoot! I still carry a Glock, run them in competition every so often to keep familiar. It's all a matter of personal preference and fit.