Just to add what REW said,,, not sure I trust them either, but especially, even if your onboard is working correctly, if it is a 15 or 20 amp charger,that can whack them pretty hard ,which also can cause them to boil. Best to use maybe a 6-10 amp ,it's a little easier on them,especially if you decide to switch to an AGM. They seem to do much better at lower charger currents.
..And as already mentioned, try to minimize complete discharge,and do not let it sit in a fully or even partially discharged condition for long. Recharge ASAP, even from only a partial discharged condition. And of course,if using a common wet cell make sure to keep it watered correctly at all times.
An AGM CAN be of benefit,but for the most part is a matter of preference and how much you are willing to spend. I like them simply because they don't boil or spill and gassing is minimal,no need to water them. They also are a bit more forgiving to sitting in a discharged condition than a wet cell ,but only a little. This spring I will be on my 7th season with the AGM I have,but I treat it with care and only charge it with a 6 amp charger. It is NOT an Optima,it's actually some no name house brand I bought at Mills FleetFarm. Otherwise as far as brands,If buying another wet cell I would go with Interstate,and make sure it is fresh. There are date codes on them,make sure not sitting on the shelf for more than a couple of months.