No they are not all equal
KR808D-1 manufacturer model with gold button - 3.7v and 5 second cutoff
Vapor4Life (current single logo ones anyway) - 3.7v 10-13 second cutoff. Note - 3.7v is 4.2v fresh off the charger w/ 3.7v plateau and then near the end of charge will drop off to 3.4. Manuals still have a hole in the middle of the threaded end but it looks blocked inside (just not sure how well)
New style - SmokelessImage, Bloogplanet, Halocigs G6 - I think these are all rubberized coating, 3.6v regulated(an even 3.6v) w/ 40mah longer charge for each battery size vs the above two, manuals have a more totally sealed threaded end and a tiny recessed button that's a bit harder to press - downside is their 5 second cutoff
Most people here use and recommend manuals - harder to damage or kill with juice leaks, easier to get a good hit. But a 5 second cutoff is a bit short. With manuals you can press the button in 1-2 seconds early so good vapor is ready when you start your drag so that leaves 3-4 seconds for the drag. If you want longer drags, you need the Vapor4Life one with the 10-13 second cutoff in their description.
I use all 3 of the above.
Cartos
V4L WOW cartos - the hottest (pretty much need a delrin or plastic drip tip instead of the end cap to not hurt your lips). Great throat hit, but the stuffing is rather tight so it's not as easy to get a big drag
V4L Coolcarts - similar to the WOW carts but not as hot
SmokelessImage/Bloogplanet cartos - bottom coil so the vapor is cooler with less hit, but stuffing is looser so it's easier to get a bigger drag.
And there are other stuffing cartos and reservoir cartos of various kinds sold at multibrand vendors.