Construct 2 is restricted to Windows only, so consider that before buying a machine.
I've dabbled in C3 on my iPad Pro and MacBook Air and I think it works nicely (more experienced users may have more to say on the matter mind you!) Also bear in mind that C3 is still in beta, and if you want to see what bugs are currently being worked on, you can check the tracker.
Both Construct 2 and 3 have free versions, so you can always try those out first! And if you're going and testing laptops/tablets in a shop, you can probably load up the Construct 3 editor on a demo machine if they're not too locked down.