I'd have to go with GP Paps X as well, I still giggle every time I use it
I take the same level of care with my devices, still have an eGo-Twist from when they 1st came out, & not a single scratch or knick. never stand my devices upright to prevent hairline scratches, lay sideways atop soft items, microfiber or polishing cloths only, etc.
however, taking care of a MOD has nothing to do with the thinness of a Nemmy's locking ring.
whether necessary or not, it's always beneficial to have 'security' or confidence in knowing you're taking preventative measures towards safety. this is the pure function of a locking ring, safety. no company would make them if it wasn't felt to be beneficial to the success of a device. does that mean it's necessary?, no, just safer & smarter option for the consumer to spend their money on as it's still easy to fire whether recessed or even inverted deep into the metal itself. please be safe out there folks.
recessed buttons that still have a locking switch:
* Atomo V2, GP Paps 2.5, GP Paps Lux, Da Copper MOD, EVOD, Nzonic, Poldiac, Vanilla MOD = 8 off the top of my head.
Br. Chi You. Carvalho. Onyx Nemesis. 2.5Lux+. Paps X. XXIX. Stingray. DNA30. Caesura.
I would have to say the titan and cronus