it all depends on your personal circumstances and choice of car.
occasionally there are deals to be had on pcp etc for cars that are not available on motability.
very occasionally there are deals that beat motability on individual models, at one time there was a special offer on an auto jeep renegade that was cheaper than motability but it was only one model in the range and not the best one. but if that model gave you what you needed it was a bargain.
the thing to remember with pcp is that they tend to charge for the slightest blemish at the end of lease and mileage charges arent low.
motability offers something thats worth a lot, peace of mind one payment and you just put fuel in and so long as you look after it at the end of 3 years you get £650. no searching for insurance deals, servicing etc all taken care of.
at the end of the day its your choice.