Size, buttons work well except center sometimes requires an extra "push".

Too large to hold in one hand if you're trying to position an item or use other equipment like a white board to reset white balance with an external slave flash.

I purchased the underwater case from our local Ritz Camera center after I'd swamped my Sealife Reefmaster D-series camera. I upgraded to the olympus for the price (really wanted an SLR) & the optics on this camera are awesome. The housing and camera are guaranteed as long as you bring them back to Ritz. The housing is nicely constructed, but with ball and arm for external flash is not something manageable with one hand. The buttons and switches work well and are intuitive if you know your camera's abilities outside of the water. I was a little concerned about the "double" O-ring system, but it has been working fine and just requires a little more time in the preparation of the camera. All and all a nice piece of equipment.