I am not familar with the foam. For those that have used it, would you say you perfer it in foam form or liquid??
Foam! Wet has one of the best toy cleaners and here's why: it dissolves lube right off of your toys. I've seen it demoed and you literally can see it working and see it cleaning your toy. The foam starts to break up your lube and you can see it dripping off your toy. In a pinch I have just used baby wipes and I've used spray cleaner when I'm lazy but the foam works great!
I love Wet's toy cleaner. Like Kate says, it dissolves lube wonderfully and it also does a good job on whatever else might have gotten on it. It spreads easily and one bottle will last quite a while. A liquid might be better for something that's really stuck-on, but I can't imagine most people having that problem with sex toys (though I could be wrong...).