1150RT vs 1150R Rockster HP

Hi folks,
I am currently test riding a few different used BMW bikes with a view to buying one. There are a couple of particularly nice ones I am looking at, an '04 R1150RT and an '04 R1150R Rockster. Radically different bikes I know, but I am kind of keeping all options open. (Radically different prices too)

I have been looking at various spec sheets on some online sites and I have seen the twin spark R1150RT rated at 95 HP and the R1150R Rockster at 85 HP.

Is this correct? Is the RT 10HP more than the Rockster?

Its probably going over old ground for you guys, but are there any common faults I should be looking out for?

Any advice appreciated,

cheers,
Rick in New Zealand