Do I NEED one? I have a 510. I carry 2 batts, 1 in use, 1 in my pcc. When my batt eventually dies (2-3 hrs later, heavy use) the other one is charged. and if for some reason i get a dead batt before the other is charged then i have my usb PT. So do I NEED a Chuck/GG/whatever else is out there?
Only you can really answer the question.
If you are pulling your hair out over having 3 batteries constantly on charge changing them every 1.5 - 2 hrs and leaving home with pockets full of them as I was then yes it is worth getting a large battery mod.
The small pv batteries are just not built to be hammered constantly day in day out.
When new they will give you 2 ish hours good vapour to a charge this quickly becomes 1.5 hrs and then 1 hr .
It also starts to become expensive when you have to replace them on a regular basis.
The larger mod type you should get 5 - 8 hours constant vaping from a battery and 2 or 3 of them should last you 3 - 4 months.
I also love the switch - never want to be without one again.