So cool! Welcome back!
For me, from the mountains, MTB more practical, good frame and wheelset is also very important.
I like carbon frame and wheelset, and have a variety of carbon frame.
Benefits: disc brake braking and the cooling effect is better than v brake!
Inadequate: disc than v brake weighs a lot! And for some oil disc and the phenomenon of oil spill, as avid juicy 3 and hayes!