I find this watch can go over a week without charge, happy with that.
I collect most of mine on a spinning bike. I can't even collect it well from cycling because there aren't enough hills in my area and nowhere I can safely go fast enough to get the kind of resistance I need to get my heart rate over 150.
Same! It is tough on the road unless you meet a lot of hills.
I like the GPS and stats that come with jogging outside but my ankles don't like it and much prefer the cushion of a treadmill. Playing an active sport seems to work really well - heart-rate spikes and the cool down period seem easier/more fun than grinding out a consistent 150 bpm. Saying that, I don't have many options for sports at present and most of my PAI is coming from the elliptical trainer.
27c, yeah that doesn't sounds like a comfortable sleeping temperature, hopefully your deep sleep will improve when things cool off a little.
I've been doing 30-minute sessions on the bike spiking it to 175 and back down to 140. I find it is better than grinding out a high plateau. I think the technical term is HIIT. It's like doing sprints.
The GPS is great, especially when doing random courses. I do have a nice running track nearby (GPS is pointless for a 400m oval, unless I forget how many laps I did). Maybe I'll hit it up in the fall a few times. There are lots of mountains near me and I find the ones that are about 500m up are a decent workout. Again, fall.