People say that 35 and 50 are too close but I find them very different. After all, a 50 covers about half the area of a 35.
For that matter, on reflexes, I find a 58 unreasonably different from a 50. And Frances loves 18 but has little time for 15 or 21 (we'd both like a WATE, though).
Cheers,
R.