This is off-topic but I think cleaning has something to do with it. The TfL 315s are a lot older still and smell a little bit musty sometimes but because they've been refreshed a few times and are reasonably looked after they feel relatively clean. 465s always seem to stink of urine (and not toilet greywater smell like lots of trains near the toilet, actual urine) and just feel really grubby, even the ones that have been supposedly refreshed, though I can't say I notice much difference.
The 700s are also appallingly looked after, the first introduced /1 units look very shabby on the outside from the months of grime buildup, you can actually tell roughly what unit it is turning up by how clean it is. A clean unit means it must be almost brand new as it hasn't had a chance to get dirty yet. The inside is much the same, Monday AM peak services running around with party debris, balloons etc littering the place, presumably from the day before. If you aren't going to clean the floors at least litterpick the units... The 700s may not be well liked but it's still depressing to see trains less than a year old look as if they have never been cleaned since they were delivered.
