presa 40w (non TC) was my second ever mod. One day i was charging as normal, and noticed after two hours the charge hadn't gone up and the thing was too hot to touch when i picked it up. I let it cool off and then it charged as normally next day and has worked ever since (this was over a year ago).. i always found it strange there was no sort of protection that kicked in for the in built battery. Anyway, heavens gift had a sale and i got the 40w TC one for like 18 dollars, in black this time (original was silver), and it's atrocious. Absolutely no tank will screw anywhere near flush (510 is so shallow), the fire button squeaks every time i press it, and the plus button is mushy whilst the minus is snappy and clicky.. very disappointed. In the same order i got the 100W one, which is huge and heavy, but not a single rattle, and sits any tank up to 30mm without overhang, as well as taking a 26650 or 18650 with adapter. But it's just so bulky.
Let me know how the 75w goes, as that is a similar size to the original 40w versions but takes an 18650.. Heaven gift sill have them and they have a 30% sale right now. I love the fire button manual lock feature and i love the central positioning of tanks, despite the ....ty joyetech 510, but mostly i love the grip and fire feel of the whole thing. If the 75w are proving to be without many rattles and good buttons, and not to heavy, i'll get one.