Mechs are the simple and works end of the
vaping spectrum.
No circuits, no regulation just a Battery holder with a Mechanical switch.
Nemesis and most of its Clone offerings is a very decent device. Solid performance and flexible in design.
Mechanical Mods are almost always smaller footprint than APVs in same battery class.
Most can also support a Kick module for Quasi VW support(no longer full mechanical)
When looking to drop to low/sub ohm Vaping a Mechanical with the proper battery is an easy decision.
The question is more What direction are you wising to go in Vaping.
As for myself, I enjoy a bit of variety and use Mechanical Mods, some with Kicks as well as my APV. It tends to keep the Vape experience spiced up and fun/relaxing. I also enjoy tinkering with different devices.