I have regularly seen on US and West African flights obese people, mainly women, who are literally so wide they have to go sideways down the aisle...they are not going to get out in an emergency and neither are the poor sods behind them...I doubt frankly they would even fit thru an overwing exit.
These people are a hazard to thenselves and to others. They should be seated on a bulkhead row close to an exit and an f/a...they should be treated as disabled and numbers limited...yet on some flights there are loads of them...
As for the experience of sitting next to one...as others have found it is unpleasant to say the least
