12-25 on 10speed here with 53/39 up front in the Peaks. Could use a slightly lower bottom end, but wouldn’t want to lose any top. Pretty much every ride I break 40mph (48.something today), and most descents are at 30+, so I spend a fair amount of time in the 12 & 13. (I stop applying useful power at about 42mph, fully redlined about 45). I’m 10 stone, not racing anybody and quite enjoy climbing out the saddle, so I don’t find the bottom end very limiting up until steeper than 1 in 4s. Winnats is very unpleasant, but doable if I really want to.
I’ll be sticking a 11-25 on if I ever end up going compact (which would be a sensible thing to do, but I keep putting off spending the cash!)