Personally, I find there is nothing more likely to b*gger up my judgement in the latter stages of approach than looking out of the side window
Agree with that, you can look forward in most types and easily see enough with peripheral vision. With a Pitts that's all you have to rely on
As for the OP's question, I have about the same number of hours, and I would say no one could ever "know" the exact distance between the wheels and the ground (not many GA planes have a radar altimeter!). Neither would you want to know exactly as other things are just as important i.e. speed and attitude.