Let's get right to it:
Here is the Rivals.com page for Montgomery, and as you can see, he is a 3-star, but with a Rivals Rating of 5.7, which means one more tenth would put 4 stars by his name. By looking at his offer sheet, you can see that Kentucky beat out the Louisville Cardinals, Wisconsin Badgers, Mississippi Rebels, and N.C. State Wolfpack for his services.
John Clay has a bit more on Montgomery, including his commitments to this point. Clay lists only 15 players committed as of now, which would seem to leave us quite a few short.
Obviously, this is another quality player of the sort Kentucky needs to be getting a lot of, and it looks like under Mark Stoops & Co., they will be.