I had the Seidio Innocase but didn't like the loose feel of it. Then they came out with the Active case which I have now, I like the look and feel of the case, just don't like the gaps between the hard shell part and the silicone that are evident at the corners of the phone, but, really, it's not a big deal, just looks a bit cheap that way. I did get the Active Case/Holster combo, but one night, I sat in the passenger side of my car, and as I sat down, the phone was just in the wrong location and the holster snapped off. Since I was angry at myself, I just threw the remains into a public gargbage can....pretty dumb, since Seidio would have shipped me a new one if I still had the old one. I never liked the holster much anyhow since it doesn't do much in the way of protecting the phone and since it seem like it wouldn't take much to just accidentally have the holster open and release the phone to the ground, so, I went ahead and bought Seidios horizontal leather pouch/case that was meant for the Innocase. No one would give me a straight answer as to whether or not the phone with the active case installed would still fit into a leather case designed for the smaller Innocase, so I just took the plunge and bought it anyway. Turns out, it works great.
Anyhow....I am not a case person myself, I usually rely on a horizontal leather pouch/case to keep my phone safe, but, in the case of the Evo I did get a case as soon as I could, reason being was the camera lense which is otherwise the main resting space for when you lay the phone on it's back. I didn't want it to get scratched up, hence the case.