Edit:
alec It causes no negative effects even after a full day of use.
Note that you've already got me beat 😉
I use a Lenovo Thinkpad E550
It does not have PWM and is otherwise a pretty good laptop.
It suffers from the dithering Intel is known for, using Intel HD Graphics 5500
, allowing me to only use it for a few hours before typical symptoms show (I don't respond well to PWM or dithering).
However, there are reports that a different ICC profile may help with this but I've yet to identify one that does (for me)
It runs linux mint fine - LM Mate was a little weird but could just be the software. Cinnamon is fine.
I wouldn't consider it perfect because of the Intel HD 5500. But for other options out there I consider it decent. If I could fix the dithering, it would be great :\
Some specs
> inxi -Fz
System: Host: core Kernel: 4.4.0-53-generic x86_64 (64 bit)
Desktop: Cinnamon 3.2.7 Distro: Linux Mint 18.1 Serena
Machine: System: LENOVO (portable) product: 20DF0040US v: ThinkPad E550
Mobo: LENOVO model: 20DF0040US v: SDK0E50510 WIN
Bios: LENOVO v: J5ET48WW (1.19 ) date: 08/27/2015
CPU: Dual core Intel Core i7-5500U (-HT-MCP-) cache: 4096 KB
clock speeds: max: 3000 MHz 1: 2400 MHz 2: 2400 MHz 3: 2401 MHz
4: 2485 MHz
Graphics: Card-1: Intel Broadwell-U Integrated Graphics
Card-2: Advanced Micro Devices [AMD/ATI] Opal XT [Radeon R7 M265]
Display Server: X.Org 1.18.4 drivers: ati,radeon,intel (unloaded: fbdev,vesa)
Resolution: 1360x768@59.80hz
GLX Renderer: Mesa DRI Intel HD Graphics 5500 (Broadwell GT2)
GLX Version: 3.0 Mesa 11.2.0
Audio: Card-1 Intel Wildcat Point-LP High Definition Audio Controller
driver: snd_hda_intel
Card-2 Intel Broadwell-U Audio Controller driver: snd_hda_intel
Sound: Advanced Linux Sound Architecture v: k4.4.0-53-generic
Network: Card-1: Intel Ethernet Connection (3) I218-V driver: e1000e
IF: enp0s25 state: down mac: <filter>
Card-2: Intel Wireless 7265 driver: iwlwifi
IF: wlp4s0 state: up mac: <filter>
Drives: HDD Total Size: 128.0GB (77.9% used)
ID-1: /dev/sda model: SanDisk_SD6SB1M1 size: 128.0GB
Partition: ID-1: / size: 102G used: 93G (97%) fs: ext4 dev: /dev/dm-1
ID-2: /boot size: 472M used: 62M (14%) fs: ext2 dev: /dev/sda1
RAID: No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors: System Temperatures: cpu: 31.0C mobo: N/A gpu: N/A
Fan Speeds (in rpm): cpu: 0
Info: Processes: 221 Uptime: 3 min Memory: 485.8/15783.6MB
Client: Shell (bash) inxi: 2.2.35