I am trying so hard to not acquire more computers, but the need to test a ton
of stuff and have a good reference platform forced my hand. Rather than do any
research I took trasz@'s recommended Dell laptop as test target and picked one
up from eBay, a Dell Latitude 7280.
 It was 65 quid with about a fiver in postage and there are a ton of them. So
many that I wasn't super discerning when reading the listing.
 
   
 
 The Dell Latitude 7280 is ~12 inch Intel laptop with a 1366x768 display, it has
USB ports, will take USB-C power (vital considering how few come with power
supplies), HDMI out, Ethernet and a nice surprise a USB smart card reader
builtin (I even have some java card smart cards
 
  somewhere
 
 I could try, I
won't, but I could).
 I let it boot windows to verify it came up and then started about installing. I
couldn't break into the bios with a key press and used the windows "reboot to
firmware" hidden menu to get into Dell's firmware.
 Out of the box all of the hardware works:
 
  | Component | works? | Notes | 
 
  | Graphics | yes | drm-kmod i915 | 
 
  | WiFI | yes | Intel 8265NGW with iwm or iwlwifi | 
 
  | Ethernet | yes | em(4) | 
 
  | Suspend/Resume | yes | (with default wifi adapter) | 
 
  | Camera | probably | webcamd wants it - haven't tested | 
 
  | USB | yes | USB-C data and power work | 
 
  | SD Card slot | yes | rtsx(4) - micro sd card | 
 
  | Audio | yes | speakers and headphone jack work | 
 
  | Media Keys | yes |  | 
 The bios doesn't lock which WiFI cards you can use - the main reason for
getting this machine was that trasz@ said suspend/resume worked until he used
iwx and I needed a platform to debug iwx suspend on.
 I had no issue swapping out the builtin WiFI for an iwx card and now I'm
portable for testing I could get pretty close to my attic AP and pull/push ~400
Mbit with iwx.
 This computer is really well supported, but its a bit of a dog. I didn't read
the eBay listing well, it doesn't have the rubber feet, but that's fine I put it
on a silicon matt on my desk. The battery is absolutely goosed, the bios lists
battery health as 9%, this was in the listing I just, well didn't really care.
 
  apciconf
 
 says it should get an hour on battery, but I haven't let it run to
nothing. I got a replacement battery so I can use this thing as a test platform
for an upcoming GSoC power management project and it being a Dell part meant
getting replacement was quite easy.
 I wouldn't recommend this exact laptop, maybe a Latitude 7280 with a working
battery and feet would be okay. It is slow as hell, building a kernel took 1838
seconds, 30 minutes is a long time for real development work.
 The screen resolution is quite low compared to modern 2k displays, but its
probably fine for programming tasks and writing. I wouldn't want to do builds
on it.
 The hardware seems quite nice apart from the rubber surface which seems to be
degrading. I don't think I got a representative laptop, if you want a test
FreeBSD machine this might be a great choice at well under 100 quid even if you
have to replace the battery.
 --
 Update
 Working on the Latitude 7280 is a really nice experience. I have replaced the
WiFi and just after publishing this post a new battery arrived. There are 8
captive screws on the bottom which give access to quite a well laid out board.
In mine there is space for a wwan modem.
 The battery replacement was excellent, a replacement was 25GBP. The battery is
held in with 2 extra screws (1 case screw also secures it), the  cable has a
pull chord from the motherboard connector. The battery side for the cable is a
little harder to remove, but no challenge compared to a glued down thing. Sure
it is a plastic laptop, but it is light and thin enough. I don't really get
Apples excuse for their stuff not being this maintainable.
 I have had thinkpads before and they've never been great while they have been
expensive. This 2018 computer is much nicer than any thinkpad I had.
 
   
 
 With the new battery this looks to be a great machine for sitting in vim:
Design capacity:    7895 mAh
Last full capacity: 7895 mAh
Technology:     secondary (rechargeable)
Design voltage:     7600 mV
Capacity (warn):    789 mAh
Capacity (low):     239 mAh
Low/warn granularity:   78 mAh
Warn/full granularity:  78 mAh
Model number:       DELL DW3WC64
Serial number:      44280
Type:           LION
OEM info:       SMP
State:          discharging
Remaining capacity: 100%
Remaining time:     8:17
Present rate:       953 mA (8124 mW)
Present voltage:    8525 mV
 
  You can find a full dmesg here.