We did the snappi thing for about eight months -- once she got chunky, I had a hard time getting them to fit, and about then I had two really gross finger-gouging incidents (those teeth are sharp!). Plus I nearly killed a handnit soaker that way! I am very clumsy with the snappi, I guess.
We (husband and I) love pins now -- you can get a really tight, secure fit, get a longer wear time on the diaper ('cause you don't need to bring the sides so close together), and they're impossible for a toddler to remove by herself. After more than a year of use I've poked myself only once, and never poked her.
We use Dritz diaper pins with locking heads; the Gerber ones from Target were awful, dull and dangerous.