I've been shooting Glocks for the past 26 years - 17 (Gen 1), 21, 26, 34, 35 and now a 43 (carry). Love them. Never had a 1911 but always wanted one. Not quite 2 years ago, I killed two birds with one stone and bought a STI Executive, from a forum member. It took a little getting used to, but I love it. So much so, I picked up a Trojan, also from a forum member, last year because I wanted to give SS a shot.
Glock and 1911's are different animals and shoot and feel very different. Glock, hands down, is one of the most, if not the most, easiest guns to shoot, not to mention the most reliable. 1911 are the coolest however! Disclaimer: I have little to no experience with other brands so this is just a Glock - STI opinion. Glock wins the easy to use, idiot proof gun. My STI's will are my favorite though - they just took a little getting used to - maybe more than just a little. At the end of the day, it's the guy working the gun that makes the big difference. I don't score any better with my STI's, but I'm still pretty much a beginner to competition.