That depends entirely on what you’d need it for, although if the intention is to use it with a microcontroller, either one will do as the exact Ohmage can be mapped to different values as needed once incorporated into a design where you can get an analog voltage read. Personally I prefer the 10k just because I know that halfway should be about 5k, quarter of the way 2.5k, etc. What’s half way on a 4.7k? 2.35k? And a quarter? Brain’s got better things to do than remedial math there :)
If you actually need one in an analog design, on the other hand, that design itself will dictate whether you’d want 10k, 4.7k, or something else entirely.
I’ll reply just to this comment, can copy the conclusion to the other one when we get there.