There is no perfect case for the 8525, but here is my take.
First, I have enclosed my 8525 in a plastic innovative case from Boxwave. the model is called "The Active Case". This small profile case still allows you to open the slide because it is really 2 seperate pieces, one for the upper and one for the lower piece.
I have been using the Sena Lateral Pouch, which has a nice grade of leather, adequate for my needs, and a belt clip that slips onto your belt, once your belt is hooked and you are ready to go. The price point is excellent (around $45.00). But, after a month or so, perhaps after using the case with my larger belt for my jeans, I started finding that the belt clip would slip up and then off when wearing casual slacks and an average belt. Recently, I had to rescue my phone from under the next car in a parking lot. On the other hand, my 8525 encapsulated in my Active Case fits very nicely into this case.
I just bought a Vaja case and here are a few thoughts. The leather quality is somewhat better than that used in the Sena case, but at double the price. The belt holder (no clip) requires that you slide your belt thru the loop in the back of the case to get it in place. So, it is impossible to have the case fall off, but the belt loop is too small to fit my jeans belt (1 3/8"). The other problem is this; with the Active Skin in place, this case is a tad tight. I have to work at getting the magnets clipped together.
As I started this post, there is no perfect solution. Consider the Active Skin as a 'backup' protection.
