Ahoy!
I just watched some YT clips about SH3 and SH4 and I really want to try it. Had to order some CD from Amazon as UK's stock is mostly empty so I am still waiting for it to arrive.
By the time I decided to join SubSim in search for some info and help.
After quick Hello I start with my questions as I believe that can be quickly answered here without spaming main forum.

Could you guys tell me what all those (TMO, RSRDC, Traveller's Mod... etc) mods do? I know it is simple question but after googling for a bit I was not able to find a answer

I would to know (in simple words as I never played SH) what are the benefits of having those updates. As I still have to wait for SH4 CD I would like to download all necessary MODs to get them ready to go on time
All The Best, Bart