I stayed at both the Intercont (Salisbury Road) and the Conrad.
Definitely go for the Conrad, as a Gold Hilton member I was given access to the lounge, free breakfast and higher floors.
The Intercont was extremely disappointing. As an Ambassador and Platinum Priority member, this meant nothing. The welcome gift was laughable. (a small bottle of perfume in an IHG box) The only positive was the view. The Intercont wanted to charge extra for sugar and tea bags as well once they were used up. Absolutely rediculous!
The rooms were in a need of an upgrade and it definitely felt like a 4 star hotel, and we were in the supreme harbour view rooms which were double the size of the normal ones, so god knows how awful the standard rooms are.