I bought my first gel cell battery in 1989, Gates made them then. Optima bought them out since then and I've installed and used several hundred since then(had a shop for 8 years).
I've got 2 in my Jeep, 2 in my F-350, 1 in each trailer, 1 in the car and 2 going into my Dodge van. The 2 in my Jeep survived winters in Wyoming, summers in southern AZ and lots of use and abuse, they lasted 8 1/2 years.
I've heard of problems with them but other than guys pulling the posts out of them in the late 80's (they didn't have a carry strap then so guys would use a post type carrier) I haven't heard of a lot of problems.
If I was buying an Optima I'd get a Red Top, they have a 3 year free replacement and then 3 year prorate warrenty. They don't leak, corrode, boil out, freeze, ever need water and you can mount them sideways, upside down or even right side up if you want.
As always your opinion may vary.