I am thinking of picking up this stock. I wanted to see what people's opinions were. I did see some people had trouble with them coming loose. Is there a fix for that?

Have one and like it a lot.  I'm 6'1" and like short lop stocks.  Mine did loosen up, but a little blue loctite solved that issue

The trouble is if you use Loctite on the screw that holds the urbino stock onto the receiver extension is screwing into the stock retaining screw at the bottom of the receiver extension. This threaded screw is nearly finger tight inside the receiver extension. The only thing that retains it is the snap ring at the base. It is unfortunately very easy to end up with the stock retaining screw stuck on the urbino fastener deep inside the stock and the main spring and plunger ejected out the bottom with no way of fixing it aside from cutting open the stock or buying another stock retainer screw.

I recently put one on mine and love the shorter LOP as I'm only 5'5" and have shorter arms than most people. As far as it coming loose, I've only shot it maybe 200-300 rounds of birdshot since putting on the stock and it hasn't come loose yet. We'll see how long it holds up.

Had one and it came loose. Mesa tactical makes garbage. Their shell holder screws also came loose and I had to have the holes on top of my benelli receiver  retapped by an armorer.  Mesa tacticals excuse, too bad too sad.  Stay far far away from their stuff if your gonna install it on $1800 gun.

I have one on my 11-48. Love it

IMHO it was a great idea but was late to need.  It was a solution for those who wanted a 12" LOP but couldn't afford or justify the cost of a factory C-stock.  By the time it was released a flood of Benelli factory C-stocks was unleashed onto the market, dropping the street price for the C-stock from $425 down to $250.  Pretty much every person with a M4 bought a factory C-stock.