'06 CAAD8, SRAM Rival/Force and fixie of unknown origin
As somebody who uses Eggbeater SLs with Sidi shoes, I have no problems at all and have never been found lacking for platform when standing up and sprinting or climbing. That said, I only ever take my road bike out if I know I'm going for a ride of considerable distance and know that the only time I'm going to be off the bike is to walk it to and from my door to the street.
The downside to the Eggbeaters is that if want to go for a short spin down the block to the grocery store or something and don't want to bother with your dedicated shoes with cleats, it can be somewhat of a pain trying to pedal on them. In situations like this, the Candies or Mallets may be of more use to you with their wider platform.
I pretty much always ride with cleated shoes, but they're inevitably the "mountain" style so I can grocery-shop, go to meetings, and otherwise walk around....so they may not provide enough support on their own, and the Candies might be a better choice for me.
If you have a problem with hot spots when using little cleats, the wider body will usually alleviate that. Outside of that, it's usually easier to ride on the pedals without being fully clipped in. You can put your foot on the pedal, start riding, and wait for the cleat to engage.
Having ridden both, I recommend the Candy's. While both are perfectly fine, I found myself irked by the definite feel of loss of power transfer from a start. On the track I find this to be even more noticeable.
Also, depending on the stiffness of your shoe and your weight and riding style, mild hot spots may occur with the regular eggbeaters since they lack a platform. Around the city, I find that they'd be perfect but for anything over 50 miles, I'd want a more stable wider platform for the long haul.