Anecdote time: I skipped Yosemite altogether (had a feeling it wasn't quite ready, and the discoveryd, wifi issues etc. had me vindicated), but El Capitan was r

Anecdote time: I skipped Yosemite altogether (had a feeling it wasn't quite ready, and the discoveryd, wifi issues etc. had me vindicated), but El Capitan was really smooth (rose tinted glasses maybe, but I remember it beating my Snow Leopard experience) and Sierra has been great from point 0. I can't say it's going to work for your Macbook, but if it has an SSD (or you can put one in it) I really recommend trying out 10.12.6. Revert to a backup if things go awry. I'm really sensitive to graphics issues. You never know if it's a bug or your GPU is going out. I'm not touching HS for a while.