Don't pay too much attention to what other people use - you'd be amazed at the number of shooters in HFT who bought a new scope just because they saw someone else with one who seemed to put in a better score than they did.
10x scopes are used in HFT mainly because people wanted to use mildot scopes and when HFT started and even now to a certain extent most true mildot scopes were only 'true' at 10x mag.
Everyone has different ideas, but I reckon a 9x mag true mildot scope is just about the optimum for HFT.
If you drop the mag from 10x to 9x you get better depth of field (so those close targets and far targets aren't quite so blurred even with at the cheaper end of the price range).
I think the best advice for you is to have a go a re-parallaxing your scope down to around 23-25 yards and see how that goes for you. Costs nothing to do and you can see if it makes an improvement.
You need to also start looking at why it is you think you missed targets - figure out what you think was the main reason (my guess would be parallax error played a pretty large part in it) and solve that issue first.
If you're mainly hunting and doing a spot of HFT then a fixed pa 3-9 scope is a pretty good choice I'd say.
I've got a little Bushnell Trophy 3-9x40 scope with true mildots at 9x mag (cost me £65 2nd hand) and it's a cracking little scope for hunting and HFT. Dead easy to re-parallax too.