I've found that attachments to the rail tend to kick off after a bit. If anything, I'd go for a guide rod laser or check out the Crimson Trace lasers. The extra step of turning a laser 'on' can be an issue .... there's a lot to be said about it being instant from your grip or pressure on the trigger.
Don't forget, learning how to shoot with open sights is extremely important and will serve you much better than a laser ever will...
Welcome aboard, mate. Enjoy yourself and congrats on purchasing a great new weapon