I have been using my case for a few days now. These are are my first impressions. I really like the look of the case. It looks and feels like the outside of an IBM Thinkpad. "Top" in my in the following review is the face where the mute button and speaker outlet are located.
The functionality of the overall design is good. I like the rubber feel in my hand and the phone doesn't tend to slide around on other surfaces. The case covers the speaker outlet resulting in a slightly muffled sound. Access to the keypad keys is very good. The bottom edge of the keypad cut-out acts like a stop or guide for my thumbs (I have medium sized hands) giving a nice reference for the bottom row of keys. The side and top buttons are slightly harder to press due to the thickness of the case and proximity to the button. There are definite edges around the side cut-outs that are that are sharper than I like. The case does show fingerprints and oily spots. I have found that wiping it with an absorbent cloth and lcd screen cleaner removes the spots.
In general fit and finish is very good. The cut-outs are precisely located. The cut-outs on the front (display) and back (camera) are all chamfered or rounded. This makes for a very nice look and feel. If I had to complain, the seams at the top corners (nearest the display) don't fit together as well as the sides and bottom. I'm guessing that this is caused by all the cut-outs in those areas. Not a major problem, just an observation.
Access to the connectors is good. Both the OEM headset and my aftermarket audio adapter fit perfectly. The usb cut-out is slightly too small for the cable I typically use but it works and that is really all that matters.
In general I am happy with the case. It's not perfect but none of the negative aspects I found would preclude me from purchasing another rubberized case from Seidio.
I put some pictures on Flickr but I cannot post a link here because I have not posted 10 times yet . Search for Blackberry 8100 Seidio or my user name rossman86.
My rubberized case just came in the mail today and it looks like I'll be sending it back. I like the case, but I have the Bestskinsever on my Pearl and I can't get the case to snap shut. If I snap the top first, it pops open when I snap the bottom. If I snap the bottom first, I can't snap the top at all.
I really like the Bestskinsever and I'm not going to take it off. So I guess I'll just send the Seidio back.
EDIT: After playing with this some more, I got the case to snap shut. The trick is to put the Pearl in the bottom and you almost have to slide the top on to get the top tab to lock.
I'll post how I like it tomorrow after I use if for a day.