Oh dear, yet another thread complaining about class 700s, - dominated by moans about the seats and lighting. Unlike som here living in the MML corridor out of St Pancras, all trains are type 700s, a mixture of 8 and 12-car, depending normally on the service. So:
seating - very much a personal choice, as a person who has to avoid slouching in seats that have inadequate spinal support, I find the 700s' seat encourages good posture. The thickness of padding may be a little thin for some, it does however work well with the overall seat design.
lighting - the 700s have enormous windows, especially given the current demands on designed-in crash protection thus with decent consistent lighting, the train doesn't plunge it's passengers into a murky light akin to a sleazy bar when entering the many tunnels en route. The lighting may have a colour temperature too high for some but it does make for very safe movement within the train, particularly for those with less than 20-20 vision.
traction system noises - the 700s are pretty quiet in use, apart from the magnetostrictive sounds of the motors, which is typical contemporary EMUs with 3 phase motors of much higher power than MK3 and earlier stock's DC traction motors. The inverters are no louder than those on Electrostars when running under 25KV ac and the warble under DC is the same as 'Desiro UK' stock running from and power source and there is virtually no transformer buzz.
track noise and ride - The complaints about squeal and howl when traversing the curve at the southern end of St Pancras platforms A & B are misplaced in this thread. The squeal is just normal flange contact that is probably slightly less with the 700's SF7000 bogies with their shorter wheelbases, than other stock. The howl is completely unavoidable, - a consequence of the two wheels at either end of a rigid axle travelling slightly different distances on tight curves. Both those noises would be a problem for any train (apart maybe for Talgos where wheels are not on conventional axles in bogies). As for ride, the 700s handle rough track very well, - much better than Electrostars which at 100mph would lurch alarmingly through the bumps around Mill Hill. The short wheelbase bogies seem to ride much better than conventional '8 ft' types. Everything on them seems to be critically damped.
livery and colour scheme - pure aesthetics persoan; taste, nothing to do with the train design
overall design concept - the design brief was for very high capacity, fast load/unloading, quiet, energy efficient, metro trains that can climb a 1:27 gradient from standstill and slot in paths on a high speed inter-city route running at 100mph. This to be achieved in compliance with all current safet norms. No train can satify all of that and meet every passenger's particular preference in seat, lighting etc.. Class 700s' duties include the busiest and second busiest trains in the UK, the 07:30 Bedford to Three Bridges (9R07) and 07:15 Bedford to Brighton (9T81) with loadings above seat capacity of 84% and 79% respectively between St Albans and St Pancras. This is regularly achieved with dwells of 45 seconds, - that's all that the paths allow betwen MML non-stoppers. Thus the extra wide through gangways and wide fast sliding doors are doing their jobs well.