I didn't find the G37's seats as comfortable as the 335i's, but the thigh support is better (though I'd rather have better lumbar support and get rid of the G's thigh shit altogether...got a little uncomfortable).
The new M37/56 supposed has awesome seats.
Past: '08 E92 335i|JB|wheels|"eater of HPFPs"
Present:'15 Mustang GT|401A|PP|Recaros|6MT
Sig pic unrelated. I like to go sideways and stuff.