In general, Linux runs really well if you filter hardware a bit ahead of purchase. For example, an all Intel machine with Intel wireless card will rarely give any trouble.
Edit: yes, it's a model you can buy with Ubuntu pre-installed.
(If someone knows which log file will tell me the exact reason behind a mystery wakeup after it happens, please share!)
https://www.kernel.org/doc/Documentation/acpi/debug.txt
I'm not exactly sure what options you'd need to enable/disable to just catch useful info.
Hopefully you don't need to enable everything, which may produce enough (realtime) logspam to make journald use a noticeable amount of CPU.
That being said, after each reboot I do need to put the machine to sleep using the power button once. After that the sleep/wake works perfectly just by closing/opening the lid. It's a minor inconvenience and I'm actually kind of loving the thing!
* bricks, but can be restarted if one opens the case and resets the BIOS.