I've now owned several King Quad 700s and 750s, and have come up with what are my preferred accessories/upgrades.
First up, I think the pull starter is a crucial. Ya, it won't start it when the battery is 100% dead, but it will start it when the battery is weak and doesn't have enough juice to turn over on its own. When the battery starts to age, or you left an accessory on, or used the winch a lot, there still might be enough life in it to get you home. I have used the "starter assist" technique several time. This is where you hold the stater down while using the pull starter. Simple upgrade, just order a pull starter assembly and basket from 2008 or earlier model.
First up, I think the pull starter is a crucial. Ya, it won't start it when the battery is 100% dead, but it will start it when the battery is weak and doesn't have enough juice to turn over on its own. When the battery starts to age, or you left an accessory on, or used the winch a lot, there still might be enough life in it to get you home. I have used the "starter assist" technique several time. This is where you hold the stater down while using the pull starter. Simple upgrade, just order a pull starter assembly and basket from 2008 or earlier model.