I see a similar set come through Peterborough in 2011 as well, (EMT colours with East Coast decals)
IIRC For a while, There where two Stagecoach liveried sets on the East Coast for a while last year. The Ex EMT EC Branded set and one on hire from EMT.
Funny how things go round. In 2009/2010, NXEC Sent ex Midland Mainline 43053 & 056 / Set EC64 off lease - Snapped up by FGW.
As for the Grammer seats v IC70s. They were good in their day, now the HST is looking as modern as ever, meeting better crash standards of today, and better comfort standards too.