I own the PT908 which is a single stack magazine (8rds), the PT909 is the same gun with a double stack magazine (17rds) as you already know. Taurus PT92 mags should work fine in your PT909 also. I am very pleased with the accuracy and performance of my PT908 and PT945 (45cal.) which is the bigger brother to both of them.
The 911,940,and 945 are the 909's relatives. So anything that goes for them would go pretty much for the 909.
The 909 is more of the service pistol size as far as length in the handgrip area as compared to the others due to adding a couple of extra rounds.Other than that controls,fit, and function are the same as the above mentioned 909 brethren.
Checking out all the old threads in the Other Guns board would bring up a wealth of knowledge and a dearth of reading. Using the Search tab for 911,940, and 909 threads would help.
Thank you very much for the opinions you gave me. I went to the store this morning and i settled on the PT909...i will take it to the range to test it. I do have another question...if in case the grip would deteriorate due to wear and tear....can i replace the grip for both left and right on the handle. Where can i buy a pair of orginal taurus PT909 grip(left and right)...the taurus website doesn't seem to have an email address where i can inquire about on getting those grips. Thank you and i'll be looking forward on your responses...have a great day.