I have used both.

Gerber Clutch:
- pluses: has a decent, useful small blade; can fit on a keychain though it's a trifle big; often found for $10 on sale
- minuses: gripping teeth don't go all the way to the tip of the pliers (I filed mine down); plier handles dig into your palm; screwdrivers are very limited; very tiny wire cutters
- overall, a very light duty tool

Leatherman Juice series:
- pluses: weight and size are pretty good; pliers are thin but useful with good wire cutters;
- minuses: tools aren't held open very securely (inadequate spring); handles aren't long enough to give good leverage; screwdrivers are pretty small; and IMO too expensive for what you get
- overall a light-to-medium duty tool

The thing is, IMO, you lose a lot of utility when you go to the mini multitools. If you can find a Sideclip or better still a PST-II (diamond file), you can do a lot more "real" work for 5 ounces. For that matter, a Victorinox paired with small needle-nose pliers would probably do more, but may not be ideal for EDC.

The question is, how light do you need to go? And what tasks would you expect the multitool to do?

My two cents' worth.