GTI is more enjoyable
I drove a 2012 GTI and a 2012 GLI back to back and found the GTI to be much more enjoyable to drive, no contest. The ride, the handling and the sound of the engine were completely different. Also, the materials on the GTI seemed higher end. Even though the GLI was about $2500 cheaper here in Canada, I went with the GTI for those reasons. Personally, I also like the look of the GTI better. I have 2 young kids and there is plenty of room in the 5 door GTI.