Which Groupset?

My housemate has a mtb with discs, ive tried and they stop fast an thats cool but ive never had problems stopping on calliper brakes and i rode to work in the snow, im not particularly heavy orfast and if pro CX riders can se then then i certainly can

You can set-up cantis to work effectively as well as discs. You dont need any more power than locking a wheel. Modulation is more fiddly but doable.

The advantage is not having your braking dependant in the state of your rims.

Disagree on the braking as Shimano mistake power for modulation and shifting performance that's subjective too .. but I'm not a Shimano fan boy

As they do with disc brakes too.