I had my son at Cape hospital in Jan 2006. Because of complications he was then transfered to the NICU at Health Park. He had to stay in NICU for a little while, so we got to experience both the hospitals at the same time. Although Health Park is a nicer building, I would say the birthing suites and level of care is better at Cape. I never thought of it as being dirty and I'm a neat freak, so I would say it is much better than your last experience there. I loved the massive birthing suite I had, there was plenty of room for my husband to relax and sleep if he wanted to and lots of space for visitors. The staff were all excellent and the security was very very good. My only compliant was that the TV didn't have a remote control!
I would get a tour of both hospitals and see what you think. But remember that you are giving birth in a birthing room, not in the main lobby!!!
Oh, I've also heard that Cape Hospital is more open to natural and alternative methods of birth than Health Park - that might make a difference to you. Not sure if this is totally true, just what I've heard.
(I'm expecting my second child in September, and will be having it at the Cape).