A classic - Iconic - In the 80's I'd have been delighted - Now dated.
It's the name that you grew up with, the communal areas lobby, bars are faultless, I booked on a BA Flight and Hotel package at a very attractive rate, maybe some rooms are being modernised... mine was clean, but dated.. Okay, so the room was a little passe, in style, non of the fittings stood out,and maybe waiting to be refurbished - however I'd expect the little things to be better - the towels and toiletries not of the quality I'd expect, En Suite was just old marble and fittings / shower curtain and shower - just dated - with a light buzzing in the wardrobe, which I couldn't switch off, Air con a little difficult to control, a mini bar with no pricing, no coffee facility - I could have asked and didn't !, the TV channel list under glass next the bed, was out of date - maybe this was a deliberate theme !! 
I didn't have breakfast as was on business and getting up early, but room service seems inline with other mainstream Hiltons.
For business - fine, for my money I'd spend the extra and go W.