I am short. I am 5ft 1 (155cm) with 29 inch legs. I can take risks and sit in most seats without my legs falling off. That isn't say I don't notice fantastic spaces. The Duchess Theatre, where The Play That Goes Wrong is playing, has tons of room. I didn't even have to get up when people wanted to walk past! I think a minor comfort enhanced what is a fun and enjoyable play but had my bottom been numb I might be less complimentary of the play. One ticket seller recently revealed it was going to ask patrons their height and recommend a seat based on it. "What a fantastic idea!" I thought until I noticed I was reading this on 1st April and then it became a cruel fantasy.
From taller friends I have heard horror stories, one friend had to stand at the back for the rest of the play after sitting in one chair became too much. I am getting to the age where I need a sturdy back but another friend pointed out that it isn't just about leg room. Some seats are so packed together you feel like one shift and you could end up on your neighbour's lap! Poor space can spoil an evening and understandably make you question what you spent your money on.
There are some excellent websites such as Theatre Monkey, which tests all theatre seats themselves, collates readers reviews and can recommend value for money seats. There is also Seat Plan, which has people review seats they have sat in.
Some agents, like London Theatre Direct, have interactive seating plans that allow you to at least see exactly where you are booking a seat. The only risk with theatre should be the production but it is unrealistic for most theatres to be able to make adjustments. People are taller than they were when many of London's theatres were built in the 19th Century and a theatre's main concern is bums on seats, however uncomfortable and money in the tills but what I can't find forgivable is modern theatres who have provided uncomfortable seating all for the sake of "authenticity" (Naming no names but personally I don't like being covered in candle wax. I am not judging if you do)
What can theatres do to improve the experience? Apart from knocking them down I think there needs to be more warnings. I appreciate a warning about sight lines, pillars, potential leaning but it would be good practice to say "Not suitable for people over 5ft 9" and let patrons take a risk on a seat but currently theatres do not acknowledge how physically uncomfortable going to the theatre can be.