Yeah that sucks with the apartment problems I remember that. You should be fine with 80. My light is on 100% of the time and my tent sits right at 78-80 and my plants seem to like it. Sounds like you're right on the money with it and have your ideal setup going!
As far as MH vs HLG I personally prefer HLG. I really like the new stuff they are releasing, kinda wish I waited for my 650r but thats not to say I'm not happy with it. I have a MH TS300 that I used for a bit and I liked it but the HLGs are just built much more solid and have great LEDs. To put it plainly on a budget I'd go with MH but if you want a solid light that will last and you don't have to worry about go with the HLG. I learned building motorcycles you get what you pay for so I tend to just follow that in life with most things like this. But yeah hope that helps! Have a good one man.