From the Crown battery website:
Pros and cons of Flooded batteries
Pros
Wet Cell batteries are typically the best choice for backup power applications, utility, and grid energy storage. Additionally, they are more cost effective when compared to AGM batteries.
Cons
Most of the cons of the flooded battery stem from the fact that they contain free liquid that requires periodic inspection and maintenance. Flooded batteries can also be inadvertently damaged in forceful movement. Extreme climates can have a greater effect on the battery life due to the electrolyte solution inside the battery having the ability to evaporate or freeze.
While flooded batteries do require maintenance, if taken care of properly this battery type will last longer than many of their counterparts.