Another two part review.
If you've never worked with gelcoat before, it's an interesting material. You have to be fairly precise with the amount of hardener to use. Too much and you're mixture will get a little glue-like. Too little and your mixture won't cure for weeks. That said, I got a good mix and am very pleased with the result. Do note you'll need to sand the stuff down after you've rolled it on (perhaps not an issue if you spray) -- it's definitely difficult to get a nice, smooth application just by hand. Gotta sand (I go with an RO sander). Also, most of these products are pretty caustic, but this one seemed especially so -- I left my leftover mixture in a plastic tub on the driveway, and an hour later, as the hardener and gelcoat's chemical reaction continued, the mix had to be like 200 degrees. (Once it fully cures, the temp goes back to normal.) Needless to say, you need to be careful about where you leave this stuff, cleanup, etc.
First time using gelcoat on a large area; used it to restore a Boston Whaler. Used a $20 HVLP spray gun with 2mm nozzle from Harbor Freight. Used "no wax" version for a first coat followed by "with wax" version. Gelcoat is forgiving of inevitable mistakes such as runs or sags; just sand them out. Easy to tape off an area needing additional gelcoat and spraying or hand applying with a spreader. Gelcoat does require a LOT of sanding, but the result is better looking than paint or epoxy.