My personal rundown and how they get assigned:
E - Educational / Lower office personnel spec
L - Office personnel you hate spec, but don't offer the E because they might complain.
T - Give this to all the technicians because they can't take care of anything and it will survive typically.
P - Give this to the engineers who believe having an RTX gpu will actually help them so that they are happy, and to the CAD operators who actually need it.
X - Smaller/Ultrabooks before the term got started, now somewhat a blurry line because T series have gotten lighter/thinner. But the X1 Carbon sure is a great way to spend a ton of money for a light laptop when a T-series would suffice.
Personally I stick to older used X series (currently x250) because I just enjoy a small laptop and they are dirt cheap now.
The case is all thick ABS.
It weighs like 2.4 kg, and the weight is unbalanced.
The USB-C charge only works at 20V, nothing less.
While charging it overheats and spins up the fans.
It came with a TN screen with terrible viewing angles, that could not be used in a brightly lit room. I didn't use the laptop for two months while I waited for a replacement screen from aliexpress.
Keyboard is much thinner, the trackpoint drifts easily.
Camera quality is worse, somehow it cannot handle sun-lit scenes. Microphone and speakers are similar to the T14.
It stopped receiving firmware updates after two years.
It uses about 0.5 W while suspended, so its tiny 48 Wh battery typically doesn't last the weekend with the lid closed.
The motherboard has design issues, a missing protection diode in the headphone jack microphone input ended up frying the CPU due to a ground loop. Meanwhile the T14 has eaten the same ground loop and even a 48V passive PoE in an accident and dealt with it by rebooting. A T450 from 2015 is still running.
- E is for economy
- L is for loser
- T is for tank
- P is for power
- X is for executive
As much as I hate Apple, they really do have product names down to a science.