I travelled on 005 and 003 on Monday - only very short hops between Bletchley and Fenny Stratford and return. My observations are that they appear to be quite cramped - possibly because of the high and wide seat backs, and the seats aren't well aligned with the windows. Other passengers commented that they were a big step-up from the 3+2 seating of the trains they'd replaced - one passenger singling-out the single railcars (presumably 153s) for particular criticism.
A further comment about the door opening procedure: the audible jingle advising passengers that they may open the doors comes on several seconds before the door opening button is illuminated. This confused the passenger in front of me, who pressed the button several times when the jingle started, and then stood there bemused when the door didn't open - I advised him to press the button again when the button had been illuminated. He said that he found the procedure very confusing. Surely this can be sorted quite easily / quickly / cheaply? I also agree with the comments above about the slowness of the doors - glacial.
My train, the 10.09 from Fenny Stratford (2S08) left on time, but then stood near Bletchley depot for a few minutes, before arriving at Bletchley three minutes late at 10.15. The guard announced that this was because we were awaiting entry into platform 6. Why? There weren't any conflicting movements that I can see on RTT. One passenger was most dismayed to rush over to platform 4 for the 10.17 to East Croydon, but got there as the doors were closing and then had to watch it whilst it stood there for another ten seconds or so, and then trundled off at 10.16 and three quarters - even though the working timetable states its departure as 10.17 and a half. To say she wan't happy is something of an understatement! Good job LNR - pesky passengers - who wants 'em anyway.
Interestingly RTT had 2S08 arriving at Bletchley at 10.15 when I looked earlier this morning, but this has now been changed to 10.11 and a half - very strange. Has anyone else seen similar discrepancies on RTT?