If you are refering to ones like the Maglula, I like mine. Saves the skin on your thumb and forefinger, plus its lightning fast. I have a few Glocks that came with a simple loader, they work pretty well also. There is a video on YouTube, shows how quick and easy the Maglula works. Runs about $30-35.
I have several different Uplula tools and love them all. In addtion to the usual ones for M&P 9mm/40S&W and 9mm carbine (Colt type), I just got one of the small ones for loading .22 magazines. Works great with my new M&P 22!