I have bought Asus twice and HP once. Now I'm going to buy new laptop and I think it will be Dell or Acer. I download manuals and check information. Hope I'll make right choice.
Most of my gaming laptops were from Acer; they're ok I guess. The BIOS on all of them were really limited though, but at least up until Kaby Lake, the firmware wasn't really RSA/locked-down, so it was easy to unlock it and flash it back (easy with a hardware programmer anyway). My last Acer had the GPU overheat though (GTX 1060 + i7-8750H) and fail, which made me scared to mess with gaming laptops from that point (I've never seen a gaming laptop that didn't thermal-throttle; everyone wants thin quiet laptops for some reason). I've bought ThinkPads mainly to mess with Coreboot. Pretty good computers for general-use. I had a Dell XPS that was pretty good too. My particular model had a 1080p screen initially, but I RMA'd it and Dell "upgraded" it to 4K (which while nice, introduced some unexpected HiDPI scaling issues and performance inconsistencies). Would buy again though. I also had a MacBook Pro 2014 for a while. Was fun to mess with an eGPU for a little while, and official macOS with Hand-off support with my other Apple stuff was pretty great. Might consider a newer x86 Macbook though in order to be able to use a TB3 eGPU, along with being able to use macOS, Linux (assuming most/all the T2 stuff is worked-out by now), and Windows. Both the MBP and XPS I had were all-metal chassis, which was kind of cool. Whenever I buy another laptop for general-use, I'll try for a metal-chassis primarily.