Get the laptop with all-slot RAM.

Yes, all-slot RAM is better. Soldered RAM locks you into whatever configuration the manufacturer chose, and you can’t replace it when it fails or gets slow.

With a soldered + slot setup, you’re stuck with that soldered amount. If the laptop has 8GB soldered and one free slot, you can only add up to, say, 32GB in that slot for a total of 40GB. But if that soldered stick dies, the whole motherboard might be toast. Meanwhile, a two-slot laptop lets you start with 8GB now, swap in 16GB later, and eventually put 32GB in each slot if you want. Total control.

The only good reason to accept soldered RAM is if the laptop’s form factor or price is unbeatable and no all-slot alternative exists. But that’s rare. Given the choice, always go for fully replaceable RAM.

Future you will thank you.