I received my Seidio Active X case yesterday. This is my first experience with a Seidio product and the case seems to be very high quality.
Protection: I would rate the protection on this very high. The biggest reason people get cases is to protect the phone and this case sure feels like it will do the job. It's a two piece case so you get two layers of protection. The first layer is a silicone layer however it feels more substantial than the regular silicone cases. The second layer is a hard plastic which covers the back and most importantly the corners of the phone. That is where you would most likely incur a lot of damage should you drop the phone.
Looks/aesthetics: I was skeptical as I like the look of this phone naked however this case has some style to it. It looks contemporary and adds a lot to the look of the phone. It also feels good in your hands. It's also not bulky which I was afraid of.
Function: I was able to use every function on the phone fine. The volume rocker, camera button and sleep button are covered by the silicone case however the buttons are easy to use and the silicone has raised bumps where the buttons are so you can feel them easily.
The bad: This case is not perfect, while it does not get stuck in your pocket like traditional silicone (that is a good thing) it does attract a fair amount of lint so I found myself wiping it off a lot. Also it does not fit in the car dock which I use. I made some mods to my dock to fit the Best Buy Rocketfish case, it's possible that mods could be made to fit this although I haven't played with that yet. The case is easy enough to take off if I need to use the dock. I don't use it daily so it's not a deal breaker for me.
Would I recommend this case? Yes. Overall it's a high quality, substantial, good looking protective case.