they are -- i have 2 (daily driver & the fuck-around-box)
my daily is maxed out -- 1080p IPS, backlit keyboard, t450p trackpad, 4910MQ, 16GB ram, and a 4g modem :P
the fuckaround has a 1080p TN, stock keyboard & trackpad, 4300M(?), and like 8 or 12 GB or something
with a mild undervolt (~ -50mV core, cache, GPU), i hit ~85 C on sustained loads (~3GHz on battery), though i've seen it in the high 90s when closed on sustained loads. i actually cooked my speakers that way, need to buy a new set, lmao. at least they can be swapped easily
i don't have the dGPU heatsink, if that's what you're asking. stock heatsink, repasted + an undervolt seems to be sufficient to tame the beast.
i highly recommend the BIOS mod if you can swing it. i run a custom coreboot build (seabios + grub), so it shows my logo on boot, has a custom BIOS password routine (rolled it myself!), and i have full disk encryption (even /boot!) for debian, with the grub in flash handling LUKS2.
my only complaint is boot times, GRUB can take nearly a minute to unlock the disk, due to non-existent SSE code. if that was taken care of, it could probably unlock in a couple seconds. (note to self, summer project!)