Greg, I have a blue top (dual purpose) that I use for various projects. It has spent time on various boats, starting generators, jump starting boats, cars. Today I used it to crank over a jetski that hadn't been started in four months. I keep it charged up on the shelf in the garage, and I use it whenever there's a 12v emergency.
They're great for a variety of applications. They will hold a charge for a long time when not in use, they can't spill, and they can take a lot of abuse.
BUT! Pound for pound, a good quality flooded deep cycle of the same size will give you more amp hours. So, if trolling battery endurance is critical, it's not the best choice. They're a great choice if you are lousy about keeping your battery water level checked and full.
