I just got (yesterday) the GoPro Max 360. I got it because had a cool dolphin encounter that was only partially captured on my Hero5. Very similar to the Insta 360 but I got it because it was more compact, cheaper, uses all my existing mounts and free next day delivery from Amazon (amazing for Perth). Lots of negative comments and reviews regarding the support and software for the 360 files (including a lengthy thread on Seabreeze) but I found it to be super slick and easy to use at least on a Mac (1 year old MacBook Air). There is a trick though which is strangely not mentioned by Gopro anywhere and that is NOT to import the media via either of GoPro's apps (Quik or Player) but rather instal GoPro Player on the Mac, unload the SD card and mount that on your computer or copy ALL files across. Then double click the x.360 file and the GoPro player app opens and you can the edit away happily. I can't comment on PC/Android but I tried the iPhone version (8) and seemed to be identical to the Mac GoPro player with the added advantage you can tilt/rotate your phone to look around and include those movements in your output file...
In 360 mode in the GoPro app you control the horizon where you want as sometimes you might not want the shot level. In standard Hero mode (where it acts as a normal gopro with either camera) the self levelling and stabilisation looks pretty slick. I tried the spin trick where you throw it up in the air spinning it as much as possible and sure enough the video remained pretty stable. The main downside I can see if you are into real quality is all video output is 1080. For most use for an old git like me that's plenty, recording full 360 deg at all times means you don't need to be looking at what you are filming and can concentrate on sailing etc and look around later. i.e. the 360 camera's eliminate the need for levelling as you can change it all later plus a lot more...since this camera has been out for 2 years now and I just bought it you can be sure Gopro will announce new model shortly with 4k etc.
I took it out on a recon session just 1 hr after receiving it. On the drive in it was in Hero mode and you can see the levelling/stabilisation. In 360 mode I dumbly mounted it to the side of helmet initially which of course blocks some view and makes the stitching between lenses occur on the helmet. I stopped and changed to the top of helmet and the footage is much better other than I got water drops on lens and the wind was non existent. Don't watch expecting a mega windsurf session as was only 9 knots. Editing is more playing with the view angles, panning in and out etc.
Would be much better using a harness mount like Manuel7, don't think I'll pay $200 for a couple of bucks plastic and an old fishing rod though.....looks like another job for the 3D printer...