Yeah, that's what I did with my M5; I got the 16GB (2x 8) version, and then took another 2x 8GB from my old laptop too.
The thing is, I'm having trouble finding a worthy replacement (this is years old now and is dying; the left hinge is on the way out, the keyboard doesn't work properly (and it's the second keyboard this laptop has had), and the power jack is ... temperamental, but that's another story).
This laptop can hold up to 4 SO-DIMMs (8GB each), 2x 2.5" HDDs, 2x M.2 2242/2280 SSDs, has 4 USB 3.0 ports (one of which is also an eSATAp port), 2 DisplayPorts, an HDMI port, a SIM card slot, SD card reader, gigabit wired Ethernet, 3 audio jacks (headphones/microphone/line-out), a Core i7-4720HQ and a 15.6" 1080p IPS matte display. It also has a GeForce GTX965M but I don't use that (it's always powered off).
I'm in the United Kingdom, and I'm having difficulty finding something that can even come close to that, without going back to Eurocom (which I may end up doing). The most important aspect to me is the large memory support (I can barely get by with 16GB for all the development work I do, so 32GB is really nice) and storage (both HDDs are in a RAID-1 for /home, and both SSDs are in a RAID-1 for / -- which was handy, because one of the SSDs failed a few months ago, and I didn't have to do anything). Avoiding the Microsoft Tax would also be a bonus.
To compare to the laptop this thread is about: I only see an option for 1 drive instead of 4 and it doesn't even go to 1TB, there's no wired Ethernet and no HDMI/DisplayPort connectivity.
The only reason I'm hesitant to go with Eurocom again is their long lead time & shipping charges (they're in North America), and their laptop keyboards don't seem to last...
Maybe look into a Clevo machine.
For example, the Clevo P775 has 2xM2 2x2.5" slots, similar connectors (missing sim card) and supports up to 64GB of RAM (4 slots). There are other options as well.
