Useful weblink to Fuller's Devonport Ferry site. Good background on stuff to do and points of interest, especially North Head & Mt. Victoria vantage points.
https://www.fullers.co.nz/destinations/devonport/
Jeeezus. After Wednesday Night Races, I was never in any proper condition to go to a restaurant - or drive home for that matter. A bit older and wiser now, thankfully. Great times though. ;-)
Hotel Recommendation:
If you're looking for a smartish-casual Hotel, reasonably accessible to Viaduct Harbour, I can recommend The Haka Hotel, Newmarket. It has a modern, younger vibe, good rooms and beds and includes Backpacker dorms and lounge area options. Reasonable tariffs too. Close...
If you like walking/hiking, visit Mangawhai Heads, about 1:40 north of Auckland. Lots of well maintained tracks and some incredible bush and ocean views, overlooking the Pacific, Bream Bay and the Hen & Chicken Islands.Good swimming in ocean or estuary waters and lots of interesting eateries...