Unless you are under 5 foot forget this airline or at least remember you will be unable to move because of space for the duration. Forget going to the toilet unless on the aisle.
Food okay if you can eat it in this confined space.
My wife is 5' 2" and I am 6 ' so if bigger than either of us go on another airline to another destination. we were on there normal A320 service in economy.
Maybe the emergency exit would have been nice but these are not held for larger , fit people and seem to have smaller passenger that could speak to the checkin clerk in there own language.Also seemed to be smaller than us. Seats with leg room were unavailable to book even 9 months out which seemed strange that all had been sold.
Pretty much “ditto” for any carrier’s Economy class on the same aircraft type. I wouldn’t single out Silkair as worse than anything else around Europe/USA, infact, service wise it is streaks ahead of most.