In reply to Cú Chullain:
...they have staff that are actually helpful and polite
...I can annoy my friend, that works there
...it's handy for odd things I forgot to get at Sainsbury's
Funniest thing I ever saw in Waitrose was a guy, who had been to Robert Dyas over the road, drop a tin of eggshell blue gloss paint on the floor of the produce section - he looked pretty red and the staff hadn't a clue what to do about it :-D