Despite hours invested in trying to learn how to use the it (searching on line for help, watching videos about it and trying to implement), it remained a frustrating mystery.

QUICK NOTES:
The laptop I received did not have the superfish malware installed.

I have not seen vendors mention that this model has bluetooth, an expresscard/34 slot, or an empty M.2 slot (for WWAN/SSD).

Trackpad- I saw a lot of reviews hating on the trackpad, and planned on using a mouse with this computer. Long story short, its by far the best trackpad I've ever used, but if I didn't look up how to use it I would be very frustrated with it.

CONS:

GPU not suitable for serious gaming (not a concern of mine)

PROS:

Upgradable- The CPU is NOT SOLDERED to the motherboard. It can be replaced with quad-core i7 parts with several times the performance of the i5-4200m. The RAM can be upgraded to 16gb. It should be possible to add a backlit-keyboard or FHD display, though I have not looked into this.

Ports- In addition to the 2 usb 3.0 ports, this laptop has an expresscard 34 slot, an unused M.2 slot (with WWAN antennae pre-wired), and a multimedia card reader. The cd/dvd tray can be replaced with a SATA tray for storage devices. The MDP interface can be converted to HDMI. Really the only ports you will be unable to emulate going forward are USB 3.1 and thunderbolt.

Screen- I was initially shocked by the appearance of the screen in windows 7. I tried to raise the resolution, only to find it at the maximum. Turns out the icons were upscaled by default. The screen looks great and gets very bright when needed. I'm not a huge monitor geek but it appears to have good viewing angles and color gamut. I also do not have problems with glare in the same locations that my prior laptop struggled with.

Human Interface- I probably would be lost if I didn't read up on how to use the trackpad, as it differs pretty substantially from other trackpads. It has no edge buttons, but rather the whole pad is one clickable button. You get r/m/l clicks depending on where you click. Taps also emulate clicks. Different actions can be triggered depending on whether you clicked or tapped, and how many fingers you used. Scrolling can be achieved a variety of ways (including with the trackpoint). The trackpad also supports gestures (up to 10 point multi-touch.)I have not tweaked the trackpad on linux to get it functioning in exactly the same way is does on windows, although thats mainly because it works very well 'out of the box' on kubuntu. The TrackPoint is similarly great, and really brings out the best of the trackpad. If you are a 'hunt-and-peck' keyboardist you will probably never use the trackpoint. Keyboard is very nice, although I have limited experience with high-end keyboards.

Linux- Every device worked with kubuntu. I've had many a laptop that had display or wireless issues, but everything was working perfectly from the first boot.

BIOS- Although BIOS is something most people care very little about, I was very happy with the T540p's BIOS. As a multi-boot user, I have had many frustrating run-ins with UEFI. This BIOS allows you to toggle legacy and/or UEFI boot off, switch which order they are tried in, and allows you to switch into a windows 8 compliance mode.

Performance- The Win7 install that shipped with my machine was slightly slower than what I would expect of a laptop with these specs. A few vendor-crapware uninstallations later and I was sailing smooth. I then installed both windows 10 technical preview and kubuntu 14.10, which performed excellently.

Battery- This uses a haswell processor, so the CPU draws significatly more power (37w TDP vs 13w TDP) then the latest-generation intel mobile CPUs (the new broadwell parts are soldered to the socket, which is a deal-killer for me as I intend to upgrade the CPU later). However, lenovo packs a big ass battery in there, and you can get the 57++ which will give you apx. double battery life. For low-light web browsing I have gotten ~8 hours. I've never done a drain-test, but it seems like you should be able to get 3.5-4 hours watching an HD movie or playing a game with middling brightness.