Perrone,
If you're in a pool practicing your skills where I think you are, I reckon you've got someone very skilled at diving and teaching checking up on you periodically to make sure you're doing things correctly. There's not much point practicing if you're not practicing properly.
Case in point: I've been busy at the pool practicing the dreaded front crawl. I was *sort of* getting better but not by much. As my progress was drearily slow, I was starting to get discouraged.
Yesterday, I had a private lesson with a new instructor. This man was amazing!! I made major progress in just a half hour! I went today to my pool to practice and boy, what a difference! I still can't swim a full lap of the front crawl but now I can swim one 25M length with no problem, and do the back crawl for the 25M on the way back with no rest break in between. (Last Thursday, I couldn't even complete one 25M length front crawl, although I had done it before.)
What about the instructor, Gray? Although I'm not a diver yet, I have experienced at least 3 instructors and 2 agencies so I'd like to comment here if I may. My thought on this is that while the agency can be important, the instructor is more important. An instructor may be an extremely skilled and experienced diver, but if s/he can't communicate these skills or the required academics to a student, s/he isn't much of an instructor. Is this the student diver's fault? No.It has to do with the diver and not with the agency.
Case in point: In my PADI course, I had trouble with the RDP. I asked the instructor to help me and he was unable to. I'm paraphrasing here but basically what he said to me was, 'I can't explain it." Needless to say, I failed a particular type of RDP-related questions on both my quiz and my final exam.
Later, my instructor's father who was also an instructor assured me he'd help me understand the questions when we went over my exam. Well guess what? He couldn't figure out the damn questions for himself, nevermind me! He had to ask a DM to help him! Was it my fault I didn't understand dive tables? No. I was never taught them.
Hopefully, I'll meet with success with my next instructor (and agency).