Unfortunately I can not answer your question but I would like to offer you some advice......
Please, please, please attend every session of PT and do your best to follow the directions of your physician. I am 29 years old and just had an appointment with my surgeon today to schedule my SECOND rotator cuff surgey on the same shoulder! I honestly feel that I am suffering due to my lack of completion of my PT.
I actually had a long conversation about the importance of PT with my surgeon today. I have been going to PT 2 times oer week since April to try and loosen my shoulder up. Like you, the pain has decreased and my range of motion is better but I am still not 100% yet. I still have pain shooting down my arm and a constant ache. Per his suggestion, surgery is my final option. Now, my shoulder issues sound quite different from yours so don't expect to have the results as I did. Matter of fact, this is a question you should ask your doctor. I would ask him what the chances were that you would still have to end up having surgery. It may be more cost effective to just go ahead and have the surgery if he tells you that you will prolly have to have surgery in the long run!