It’s the battle of the entry systems! The classic back zip is easy on/off but can let in more water. The chest zip (or zip-free) is the modern standard for most surfers—way better seal, more flexibility, and less flushing. Zipless (or entry systems with minimal zippers) are super flexible and comfy, like a second skin, but can be a mission to get on and off. For performance and warmth, chest zip is king for many. For maximum flex and you don’t mind the struggle, go zipless.