Got on one today (123?) and thought I'd give a quick comment.
Inside it looks exactly the same as the other FCC 313s, with the obvious exception of the seats. From the outside, it has the same vinyls as the other 313s (so not the newer design on the 321s). That makes sense, for a uniform design and the fact they could just reuse the existing artwork file!
I have to say that the low seats do totally transform the ambience, and to be honest I don't think in a good way. I boarded at Potters Bar and sat at the far end and realised that you can now see everyone - and they can see you. It's like a tube train, but for a longer journey, and you find yourself being stared at. It feels odd, given the high seat backs usually shield people. As the train filled up nearer London, it became less of an issue.
But, before that at Hadley Wood, a muslim guy got on and someone in the next row looked at him for a while and then upped and moved to the next carriage! Seriously, do people STILL feel uncomfortable when they see someone who looks similar to the pictures of the 7/7 terrorists? He'd sat down and started reading The Sun.. (maybe it was his choice of paper then!).
When I walked through the train to get off, I also noticed that some of the verticle poles from the seats to ceiling were loose, and the wheelchair area is in a different place. Not only that, but the area under the pantograph (where the wheelchair 'space' now is) has almost nothing to hold on to!
The downside is that wheelchair users will be confused with the different positioning, the upside is that the area has no tip-up seats and will take lots of people in busy periods, as long as a buggy owner doesn't get on and expect to take it all up.
Also, the seat cushions have been changed, but they haven't cleaned the seats themselves (which are filthy and worn) and I could also see that many base cushions were loose too - as in not fitted securely.
