Videos
For context, I'm coming from a T495 and I also have a 14 inch M1 Pro MacBook Pro as well as an Asus G14 gaming laptop. I run Fedora 36 on both ThinkPads.
First of all, I love the form factor. It's insanely lightweight. Even my iPad Pro with the keyboard attached is much heavier. The display is also really good, much better than my T495. Well until you compare it to OLED and mini LED screens of course but for a regular IPS panel, it's phenomenal. Not to mention it's matte which I prefer over glossy screens. The keyboard has less travel than my old ThinkPad but is still alright imo.
As for battery life, I'd say the Nano (mine has a Core i5 1240P) is more or less on par with my T495 which uses a Ryzen 5 3500U. That's about 4-5 hours of normal use like browsing the web and watching some YouTube videos. Keep in mind that this is with Fedora's power saving mode enabled. In other words, battery life is not great but at least it's not worse than my T495. That being said, I get significantly better battery life (at least two more hours) on my G14 despite it being a gaming laptop. Unless I'm actively gaming of course. As for my MacBook Pro, its battery literally runs circles around any of my other laptops. That battery can last for DAYS with normal use.
I haven't checked performance all that much yet but benchmarks are all over the internet. It seems like Intel tried their best to match the performance of the M1/M2 chips which they've achieved but at the cost of increased power consumption. The new E cores don't seem to be helping a lot. In fact, you can hear the fans running on the X1 Nano even when just watching YouTube videos. They're not super loud or anything but they are noticeable.
I honestly think unless you need to run x86 software (which many of us do), I feel like most people really are better off just getting an M1 or M2 MacBook. Alder Lake has similar performance but when it comes to power efficiency, Intel just isn't competitive. You can only do so much with 10nm when both of your competitors are on 5nm with one of them using a completely different architecture which is more efficient to begin with. Marketing 10nm as "Intel 7" is also incredibly misleading. It's a shame the X1 Nano isn't available with Ryzen 6000 CPUs which I guess would be somewhat of a middle ground, or even a U series CPU for that matter.
I still like the X1 Nano despite all of this however.
I got the X1 gen 2 with the 12th gen i5, I heard about thermal issues on the 11th gen, and wanted to try the newish 12th gen one instead with the E cores.
Docked use, and non docked use
I run windows 10 slimmed down and personally debloated it, I mainly use it docked through thunderbolt 4, with 2x external 1440p monitors running at 99Hz each, which makes interaction buttery smooth. (I cant push both past 99hz)
docked, its enough for office apps, browser, and outlook. Anything more like 3d programs (like CAD) it can do but a desktop might be better for these process intensive calculations, especially when you need to do data processing or simulations.
Battery
When using off dock power, the battery noticeably goes down as you carry it around. I wouldn't use it on battery for more than 3 hours as the charge level goes down noticeably after a few. Defiantly don't use it seriously for many meetings in a row without a large battery bank with you to charge it on-the-go.
Build quality
Its really thin and light to carry, the lid is weighted properly and satisfying to open with one finger. The track pad is smoother than glass, your finger glides on it like some sort of super-teflon. very nice.
The keyboard is a bit small for my large hands but I can take the compromise for portability. The speakers are top class, and so is the screen at 12 inches, and nearly 2k resolution.
Its a good tablet sized computer to use a browser and office apps on. Docked, you are going to always be limited by that 16gb of soldered ram, so its usefulness as a device for multitasking is limited to a handful of chrome tabs and profiles, and some office apps. On battery power, I wouldn't use it for more than as a browser or maybe Microsoft Word/Excel.
Its a good thin laptop to use for terminal consoles for ssh, or probably IDE programming (if you can handle the small keyboard)
Personal Con's
My only gripe with laptops nowadays in general is that the smaller 14 inch or smaller ones, usually have very small arrow keys, which is not nice when you are a daily ssh user. One thing that can happen on these keyboards the Nano's have, is that random keys can develop noticeable loud creaking/squeaking. I read online about it and apparently it can randomly happen and it just a "quirk" of the Nano, and newer carbons. My down arrow key started squeaking. Annoying. It wont always, but if I spam down arrow, it'll squeak after about 5 times and get progressively worse till the point where the entire office can hear it.
Oh also, the left side of the keyboard gets noticeably warm when typing on the laptop, thats probably the processor heat. Not great not terrible. Its distractingly hot to the touch when typing but it doesn't burn. In the winter its a good hand warmer
After notes about docked usage:
A few notes about using it docked, Im not sure if im a noob or something, but when I put it to sleep at the end of the day, and take it home, the next day I come back with it, it seems to have to power up from a cold start, and not wake from sleep. I assume it shuts itself off completely or goes into some kind of hibernation.
The annoying thing about this cold-start is that if I have it plugged into the dock when its starting, it makes this really *Really* loud chime through the speakers.
Also, maybe im a noob at docked laptops, but simply plugging the dock in, and pressing the power button doesnt turn it on, I typically have to open the laptop, let it wake up, then dock it, login to windows, then I can close the lid and use it through my monitors and external keyboard. The process can be made a bit smoother imo, but idk how.
Other recommendations
For something more powerful and robust with a bigger battery, bigger keyboard, but still thin and light, consider the X1 Extreme gen 5. thats the one I want to try next