Pawel's places is a fantastic alternative to a hotel at Heathrow; right around the corner and you get a lot more for your money.
The flat is clean, comfortable and had all the amenities you'd need for an overnight or longer stay. It was perfect for us as we had an early flight out from Heathrow but would also suit visitors to London as it has good transport links are to Paddington.
One small word of warning: the stairs up to the bedroom are very steep and the bannister is a little shaky. If you are worried about this, I think the sofa is a sofa bed so you could always sleep on that.