Over the years I've been a consistent user of Thinkpads; early on because I liked the keyboards, but then later just because I wanted hardware that would last a long time rather than a machine with a soldered-in battery that's designed to be more disposable.
My most recent device was a Thinkpad X301 built in 2008 which I started using in 2016. While it's no speed demon, using Firefox with uBlock Origin configured to block 3rd-party scripts by default left it feeling quite usable for my purposes, and the physical design of the device was perfect. They used a rubberized coating for the chassis in the X301 that I haven't seen in any other model that feels really nice on the palm rest. Unfortunately while nearly every component of that machine has withstood the test of time, the battery has not. The original battery's charge is down to around 90 minutes, and while it's swappable, working new batteries in this form factor simply cannot be purchased for any amount of money. I bought from two separate vendors claiming to have original batteries, but both of them sold me a battery which ballooned up and became unusable after a month or two.
When I started to look for replacements I was dismayed. So many of the newer models had fallen into the Appleization trap—everything must be made as thin and as glossy as possible at the expense of every other concern. I don't want a thin laptop! I want a laptop where I can look at it and see what's displayed on the screen instead of my own face staring back at me. It seemed it was still possible to find a model with a replaceable battery, but even this basic feature was becoming increasingly rare.
A couple years ago I became aware of the MNT Reform laptop, and it seems like the perfect antidote to the mistakes the entire industry seems dead-set on repeating. It's a laptop that's focused on open design with schematics freely available and all parts easily serviceable by the end user. Finding this was like a breath of fresh air; it's like someone was finally listening to my frustrations.
The MNT Reform has been described as "the anti-macbook" which I think is fitting, but ironically I prefer to think of it as the Apple ][ of laptops (in a good way). If you're like me and you're fed up with thin laptops, you will be pleased to see that this machine is chonky. It has to be in order to have room for its three most unique features: a mechanical keyboard, a trackball, and a standardized 18650-cell battery bay. Originally the batteries were what caught my attention after all the trouble I'd had buying replacements for my Thinkpad, but when I saw the mechanical keyboard I knew I had to have one. (But also: can we talk for a second about the audacity of producing a laptop with a trackball? Much respect.)
Part of having an open design is having everything documented. While you can get the schematics for everything from the motherboard PCB to the 3D printed trackball buttons, the part that nearly everyone will benefit from is the excellent Operator Handbook which describes the usage of the system in detail.
Other than the thick size, perhaps the most eye-catching feature of the Reform is its transparent bottom plate, which is laser cut from acrylic. Similar to the open lid of the Apple ][, it invites you to take a look inside and reminds you that this machine isn't magic: it's wires and capacitors and screws and connectors. It's physical parts you can understand and control.
This machine isn't perfect though; there are trade-offs. The four ARM Cortex A53 cores in the CPU do not perform any out-of-order or speculative execution, which means they are not vulnerable to attacks like Spectre and Meltdown, but at the cost of speed. (I'm using it mostly for chat, email, and developing the Fennel compiler, and it's plenty fast for that.) The lid closes with a satisfying magnetic snap, but it doesn't have a lid sensor, so you'll have to turn off the screen yourself. The stock wifi antenna's range is quite limited. (But you can easily replace it!) Suspend is currently not super reliable, but there are ongoing efforts to improve that.
The keyboard is ... well, it's head-and-shoulders above any other laptop keyboard I've tried. Instead of a comically huge space bar, the bottom row is broken up into a reasonably-sized space bar plus several other useful keys. But it's still frustrating in a few ways. (Note that I'm a major keyboard nerd who has spent a lot of time getting my keyboard setup just right and I am far more picky about this kind of thing than most people!) While you can reprogram the keybord firmware to reassign keys with ease, the physical layout is very awkward. It has a conventional row-stagger which is not great but also not unusual. The problem is that in most row-staggered boards each row is offset from the one above it by 1.25 key widths or so, and on the Reform it's 1.5. Even 1.25 is too much (zero would be ideal), but 1.5 makes it so you have to contort your hand even more to hit keys on the "ZXCV" row.
Of course, it's a hackable laptop! Reprogramming the firmware to rearrange the keys can't fix problems with the physical arrangement, but I've built hundreds of keyboards by hand, so I planned to do design and construct one from scratch for my Reform when I got it. Unfortunately it's a little more complicated than I anticipated; the stock keyboard is integrated with the system controller which is involved with powering on the entire system and controls the OLED display containing the battery indicator, etc. I couldn't just adapt my existing design for a new form factor.
Luckily the folks at OLKB announced they were developing a kit for an improved keyboard with no row-staggering. I'd prefer an ergonomic design, but this is still a big improvement over the stock board, which is itself light years beyond anything I've ever used in a laptop before. I'm looking forward to building one out.
Overall I'm thrilled with this laptop. It's available both as a DIY set which needs some assembly (just screwing things together and plugging connectors; no soldering) and as a prebuilt laptop, but honestly if you're anywhere near the target market for the Reform, you're probably going to enjoy the assembly process and are best off skipping the pre-assembled option. In the end the Reform is a powerful antidote to the user-hostile trends which have prevailed in computing over the past decade or so, and if you're anything like me and you don't mind a little tinkering, I can't recommend it enough.
 Starting with a T60p in 2007 followed by an X61, then an X200s, and finally a X301. I took a brief detour with a Samsung ultrabook but the keyboard was so unpleasant that it didn't last long before I sold it.