It all depends on what you want to achieve.
More teeth in the back means a better climbing gear but that also means more expensive rear gear, and probably more speed (11 or 12 speed gear set vs what you might already have 9 speed or 10 speed)
gordone said:
I have a full suspension bike with TSDZ2, and have a rear cassette 11/42.
I’m planing to use the bike to work, but also offpist on tracks…