I've stayed at the Mercure that used to be a Novotel (the one on Customs St, opposite all the strip clubs) - it was a dump, likely still is.

Most CBD hotels in Auckland are crap - the Crowne Plaza, that Mercure, etc. I'd go straight for the Hilton down on the harbour. It's souless, but at least it's quality (and clean). Not directly opposite strip club row, but within walking distance if that's your thing.

The Novotel Ellerslie is WAAAAAAY out of town near the racecourse. OK hotel if you're just there to meet somebody at the hotel, useless otherwise.