Just thought I'd throw my two cents in as I'm in a very, very similar situation as you.
So to start... I started riding when I was 14, did some racing through teenage years, then stopped. Moved to Whistler to chase the dream for a couple years (pre bike park) then the North Shore after that dream was crushed (haha) (late 90's). Started riding a bit with an old Rocky Mountain hardtail with a 2 inch travel fork... and had a blast. Around that time the Whistler Bike Park opened up, so I bought a bigger cheap Brodie DH-ish rig and had a blast for a few years on the Shore with trips to the WBP.
Because of life, kids, moving for jobs etc... was rarely on the bike for a period of about 10 years or so. Then moved to Victoria 2 years ago and am just getting into riding again. Took my old 45 lb monster for a couple AM rides with friends who are all getting back into things this fall and realized very quickly that I needed a new bike haha!
So I, like you, have been researching like crazy, reading reviews, posting on forums, talking to friends, demoing bikes etc, etc... trying wrap my head around the new bikes, the tech, the angles the 1x drivetrains, etc!
The terrain I'll be riding is mostly AM/Trail crossed with aggressive XC and dabbled with some good Enduro, but I will also make a few trips a year to the Mt Washington Bike Park as well as the Coast Gravity Park and a couple days in Whistler. I'll probably even get a couple days back in my old stomping grounds around the shore.
One other factor I considered while shopping, since I am also only able to own one bike (well, one mtb... I have a commuter as well, I do live in Victoria), was that it needs to be able to work well on a couple extended mtb trips with friends to various parts of BC that will be AM/Trail/Aggressive XC, where I'll need to be able to keep up more on the up and traversing sections and then still have energy for the down!
Anyway, like someone mentioned, I kept my eyes open for good deals on 2017 rides and managed to find a great deal on a 2017 Norco Sight (27.5)... and it was such a good deal I was able to swap out/upgrade/lighten a couple of the parts as well.
Have only taken it out for a couple quick rips... but so far, it feels perfect. 140 (5.5 inches) & 150 (6 inches) is more than enough. Hit a pretty aggressive enduro trail and it handled it amazingly well. Part of it may be me being rusty and slow, part of it may be me being out of touch for 10 years and the tech making leaps and bounds, but part of it was also the bikes capability. And honestly, at my age, with my responsibilities, I'm not going to get out enough that my skills will improve that much, so it feels perfect. The weight is also great... but I wouldn't want it any heavier! And I feel like I still have a ways to go before I'm able to take this bike to it's limits.
My thoughts on 29'rs... the bikes I demo'd were great bikes... just that none felt right to me compared with 27.5. Hard to describe, but the 27.5 versions I rode just felt more... fun I guess? Lively? Jumpy? To each their own though.
Hope this helps... happy hunting!