I love my rDNA mods (30 and 40 now). The build quality is awesome and they fit the bill for everything I use. Kayfun L+, Russian 91, 454 Big Block, Plume Veil 1.5...and this Friday a Squape R that I'm looking to try my first nickel build on. It all depends on the kind of vape you want of course. I've looked at getting a mechanical, but more so for a really clean look on my drippers, but with how well my DNA devices work it hasnt ever really been something I am in a hurry to do.
Although, if the temperature control of the DNA40 (read up on it and maybe watch some vids) interests you in all, there are some gtreat MODs out that carry that chip in them. If not, IPV3 or Siegeli 100W will probably both be more than enough, and besides being overall safer for less experienced vapers, offer a lot more options than going strictly mechanical. Although nothing LOOKS as good as nice mech mod with a dripper on top, haha.