It's not that far from T2 at MAN to the Raddison (which is mid-way between the terminals via the covered walkway. It's actaully between T2 and the train station inbetween the terminals).
I'd say it's a 5 min walk from T2 check-in to the hotel (possibly even less). It's quite a treck from T1 and even more of a treck from T3 but if your in T2 it's very close.
Have a look at
this map of MAN. The Raddison is the lime coloured T-shape building under where it says 'Malaga Ave' near the centre of the map.
Regards