Actually the impact has a ton of protection from drops. I have dropped my phone a ton of times in the impact and have zero issue with it in that regard.
The impact picks up way too much lint but other than that it is a great silicone case that offers a ton of protection.
To note, I have a Wrapsol Ultra on my phone that I got from Amazon for 10 bucks. With that on (including the sides) the fit of the Impact is actually a fine fit with little movement. With the phone naked, it is loose internally.
So for 20 dollars (the Wrapsol and the Impact were 10 each) you get a great protective set up.
As for the TC's question, if you can withstand the scratches (get the white one) the Candyshell is a simple solution that will protect with little issue.
The commuter is good but the silicone stuck to my pocket when I used it and the port cover on the bottom was a little loose. Also I had to physically bend the plastic shell into place since it was too loose over the silicone.
With that said, I used the commuter for a longer period of time than the Candyshell. It actually feels a little more solid than the candyshell not to mention thinner. The candyshell is a simpler case that is a no muss no fuss style. The commuter is one of those that takes some time to get used to but I think it will provide better overall protection.