Have to admit that I have not read the newest edition so I cannot really comment. I was fortunate in that an edition was published right at the beginning of my residency and I used that one all the way through. I'd think that while 2014 (date of publication of 8th ed) to now is not such a big difference, 2025 (when you'll be looking to finish residency) to 2014 fairly big one. I think that if you are wedded to hard copy, I'd lean towards buying the newest.
That being said - I don't like R&G all that much. For many programs it is the bible, so it's hard to get away from it. Still, if I had my choice I'd choose Skeletal Trauma. I just always felt like it made more sense, particularly as a junior resident - R&G can loose the forest for the trees sometimes. That being said I'd take Rockwood and Wilkins all day - that got me through a call shift or two.
If you could, I'd get used to reading electronically. I was like you at the beginning of residency. Then I bought a lightweight laptop and started reading on it and taking notes on OneNote -- if you get in the habit of taking postop notes immediately, saving xrays and tips and tricks, you can get a lot more out of residency. It'll also save you money on textbooks.
Oh - and see if your residency can get you signed up for Johnson and Johnson (previously Depuy) future leaders. You do online courses and accumulate points which you can trade for textbooks. This is how I got my copy of Weisel - got volumes 1&2 one year and 3&4 the next. Ask you chiefs about it. This could be a way to get R&G for cheaper (get vol 1 this year, vol 2 in 2021, buy R&W).
