The Millennium Pro is the thrid generation in the Millennium series. The PT111 was first in 9mm. There are now offerings of the Millennium in .32 ACP, .380, 9mm, and 40 S&W. The Millennium PRO is offered in 9mm, .40S&W, and .45 ACP.
The first generation of the pistol suffered from frame/grip cracks at the rear of the frame. This was blamed in weak polymer chemistry and was corrected. Thus, the second generation.
The third generation -- or PRO model, has a redesigned manual safety level, a larger takedown pin, and "memory pads" on the grip. There may have been some work on the internals too. I dry fired a couple of second generation PT145s when I was shopping. The PT145 Pro that I bought had a much smoother and lighter trigger pull -- although they all have a long DAO pull.
It fits my hand well. Even with the double stack 10-round magazine, the grip is comfortable -- more so than the Bersa Thunder 45 with only a 7-round mag that I traded in on the PT145.
The small size, narrow width, and 23 ounce empty weight make it a great choice for concealed carry. The manual safety with the long DAO is unnecessary in my opinion, and I tend to carry it with the safety off. But, it is nice to have I suppose.
Leather for the PT145 is limited at present. The other PT versions are slightly smaller, so holsters available for those will not fit the PT145. I've opted to order the same Kydex paddle holster by Blade -Tech that I use with my HK P7 and Steyr M40/M357s.
During range tests, the accuracy with the long DAO pull was unexpectantly good. I was able to maintain 4-6" groups at self defense ranges -- shooting at self defensive rates of fire. When used from a rest, I was able to obtain groups of 2 - 2.5" at the same distances.
I performed some "wet pack" expansion tests, using the Golden Saber 230 gr. and the PowR'Ball 165 gr. Both expanded consistenly out of the short barrel and had good penetration. Here is the PowR'ball that was fired from my PT145:
I was so pleased with this round's performance, I decided to use it for carry purposes. Choosing it over the Golden Saber, reduced the fully loaded weight (11 rounds) by 715 grains -- or roughly the weight of four more PB rounds.
Here's Taurus' webpage on the PT145 Millennium Pro:
http://www.taurususa.com/products/product-details.cfm?model=145SSP&category=PistolHope this helps.