Was using back zip until I converted to front about 6 years ago. Front zip fits so much better for me since I don't have that empty space in the lower back. There is also a high stress area on the lower part of the zipper on the back zip. I'll never go back to back zip, especially with the newer stretchier material. Just roll it down half way, step into it, roll it back up(like a condom) and zip. It does take a little practice but becomes routine quite easily. Front zips just seem to fit so much better. To those of you trying front zip for the first time. It's much more difficult putting one on in a surf shop where you are usually perspiring to some degree.
A little off topic....one thing to watch out for when buying a suit for kiting....make sure there are no seams where your harness will rub. Doesn't take long for those seams to fray.