The Mallet-C is a great pedal for picking up after a dab and having something big enough to mash your foot back onto. Once you're ON the pedal it's pretty easy to wiggle your way INTO the cleat. In fact becase of the concave design of the pedal, it's difficult to ride WITHOUT clipping in.
Don't think this for a second that this is a good platform pedal ... it's not. These pedals will only grip your shoes if you wear a VERY lugged tread. This is by design as the edges of the pedal are design to make contact with your shoe in order to eliminate the "hotspot" underneath the cleat. If the edges of the pedal grabbed at those points, you would not be able to twist your foot out of the cleat.
All that having been said ... I LOVE my Mallets ;-)
Regarding assymetric clips (one side flat, the other side a clip-in mechanism) I don't care for this concept. When one places your foot down you want to be able to ride as opposed to figuring out that you've got the wrong side and you have to flip it. For technical riding there is no point. Either use a flat pedal, or use a clip in.
One more option that exists is the AtomLab Quickstep Pedals. These are the "holy grail" of clip/pedal combos. The clips grab the inside of the cleat instead of the outside. So if you stomp on the pedal without a cleat, your shoe pushes the cleat mechanism method out of the way and your shoes seat onto the pins. These are the only clip*/with flat out there that actually act like flats.
* Clipless pedals are NOT clipless. Otherwise how could you clip in. The terms "cageless" or "strapless" or "ball-clips" are more appropriate.