Do you need a particular seat (s), or are you not fussed? If not fussed, then use the online check-in (which puts you in Group D), although unless you can cram everything into a laptop case (managed three times last week!), you'll still need to check in your case. You can do this the night before, I've never used it but did read about it in their magazine a few months back.

I was in and out of STN at the weekend just gone - no problems at ANY stage (Air Berlin check in took 5 mins, security less than 10, passport control on way back in about 5). We didn't have any checked luggage coming back, but there were bodies everywhere and no movement on the conveyors. The worst queue of the whole trip was the queue in WH Smiths for bottled water (use the pharmacy counter at Boots instead!)