I started trying to learn this piece around the age of 19, before I was really ready. It didn't take long for the famous first section, however the middle part was another story altogether. I now wish I had waited longer before trying to tackle it, as it took me another 30 years to unlearn all the bad habits I embedded while I hacked away at it.
The most difficult section (and the main point of the etude) is the series of 6ths rising and falling in both hands. Like ANY new difficult piece, the secret to success is slow, slow practice, over and over, aiming for perfect note accuracy at a very slow speed. It is not glamorous and can feel very tedious at times but it will bear very good results in the end.
I think the point about all Chopin etudes, which it took me a long time to grasp, is that by learning to tackle their technical difficulties will make you a better player. It's a process, as well as an end result.
The depressing thing is that Op10 No3 is seen as one of the EASIER etudes, but it's not a bad place to start if you're going to learn any of them.
Most of the etudes will help develop your strength and flexibility in playing, if you tackle them sensibly and can keep your discipline with the slow practice.
Good luck!
Topic: Learning Chopin Etude op 10 no 3