With the current generation of laptops, the problem is the controller chipset. If you're not extremely careful, you will likely buy a machine that can only take up to 16 GB, no matter how many sticks you can attach - only the very few top-spec big-ass "portable workstation" models can run up to 32 GB, and if you're dropping money on those, you're likely to go full-spec straight on anyway. That's been the situation for several years now.

So no, sticks vs soldered DIMM doesn't really make any difference in today's market for people who want more than 16 GB of memory.

(On the other hand, soldered battery is stupid and I tolerate it only because they're really good batteries.)