I agree with most that 150s are awful but their one saving grace is that they have a number of single seats which are handy if, like me, you prefer not to have anyone sitting next to you.
For me the worst train must be Northern’s (relatively) new 195s – it’s as if Northern made a list of all the bad things about other units and combined them to make the most uncomfortable train imaginable.
Hard, uncomfortable seats, bumpy ride quality, too many tables and not enough airline seats, tiny bins so people leave their rubbish out, a bike space with pull down seats which is inevitably occupied when you get on with a bike, obtrusive TV screens flashing up constant warnings about things you don’t need to know.
Add to this the fact that many have only two coaches on routes where a minimum of three are needed and only one toilet (the 158s they replaced had two) and a 195 really is the train from hell!