They're not bad but there are better options out there such as gookinaid:
http://vitalyte.com/ or Nuun:
http://www.nuun.com/. If you choose the Gatorade route get the smaller containers. The large ones let moisture in too easily and toss in a couple dessicant packs. If you don't after a while you'll have to chip it out to use it. Another good option is emergen-c:
http://www.emergenc.com/ although my packs have gone stale after about 6 months, again absorbing moisture. I'm now keeping them in a vaccum sealed bag with dessicant packs.
HUGE +1 on the Vitalyte/Gookinade. Screw gatorade!
Seriously, that stuff works MUCH better than gatorade. I first found out about it on a 3 day backpacking trip in the Grand Canyon. Got to Phantom Ranch at the bottom. Aside from first buying a half dozen ice cold beers and downing them (bad idea when you're dehydrated. We barked at some deer later that evening as a result...) I noticed that I hadn't brought any gatorade/mix with me. They only sold the Gookinade down there, so I picked some up. To say the least, the only way to get hydration INTO your system faster is an IV.
I've seen it available in small tubs of powder on the REI website, but I always just buy it in the individual packets. After having bought a large tub of gatorade mix at costco some time ago and finding that it turns to crap rather quickly, I'll not go that route again.
To this day I always keep at least three packets of Gookinade in my backpack when I'm on hiking, along with a .75L CamelBak bottle of water for mixing it up. (This is in addition to the 3 liter bladder of water of course.) That gookinade setup has saved my own ass a few times, and definitely kept a hiking partner from getting badly dehydrated on a recent trip. Buy 12 or more at one time at REI and they give ya 10% off too, plus your REI dividend cut as well.