Since this is a Variable Wattage as well as TC type device with a standard 510 threading you can try out any tank you want. You simply start off with the wattage set to the lower end and then even have the option to adjust the resistance. Was tinkering a bit with that option earlier.
Since this is a 75w capable mod you will first want to know where the best as well as maximum wattage capability is before simply cranking it up. With the vinyl sleeve over it you can still see the battery charged by way of the eGo 510 to usb charging cord provided while the battery cover is magnetic if you choose not to use either the black or white sleeve provided in the kit.
The 18650 recommend here would be for a 10A High Drain not 25-30A battery being overkill like the Panasonic NCR18650A 3100mah flat top battery due to the tight fit where a button top would likely have a big problem! There's hardly any slack there for any longer then flat top type battery. You can find them for only $7 at Orbitronic and are put to use here on the 50w SMOK BEC Pro as well as a few box mods having seen great results.
PANASONIC 18650 NCR18650A 3100mAh Li-ion battery | unprotected | Made in Japan | Orbtronic USA
The look and feel of course is quite obviously different from the Guardian II! Unlike the two wattage ranges and need to click the cover, top, button, wattage adjustable type top three times for switching back and forth between the 6-10 and 11-15w modes with the 6-10w blue and 11-15 white as far as how the led lights up this one is based on the BEC Pro with Bluetooth capability as far as adjusting everything on a smart phone once you download the correct app.
The screensaver options after you take puff is adjustable from15 seconds to 240s as far as displaying the time in the 24hr mode only. There's no am/pm option for the time and date function. You can also opt for the simple mode which shows the watts while pressing the fire button and time when not. The normal shows the battery level indicator with the watts and resistance.
There's also the Stealth mod where nothing is displayed on the round lcd screen as well as being able to spin the display around a full 180 to be facing away from you. Makes it look more impressive for those around you I suspect being the reason for that one.
There are actually five not four vape modes besides switching beteen the TC and Watts but also the Mild, Soft, Normal, Hard, and Maximum mode I had forgotten to include earlier. The type of coil is another thing however only adjusted while in the TC mode and as well as the display settings including increasing/decreasing the contrast you can adjust the puff timer including seeing that set to Never for Unlimited! This thing is loaded with options!