Update Oct 2012
After a few months of regular use the press studs at the bottom of the case to open it up have become unbelievably stiff! Its got to the point of being a real stuggle to open the case and a devil to press the stud back to close it. I had to press so hard and with so much force it caused the camera to switch on!
There's 2 studs and therefore 2 ways of opening the camera. The first stud is unusable so I've switched to the 2nd stud. Once that becomes unusable I'll have to throw the case away!
I can't see any issues with the studs - no dirt or anything else that may cause problems. Not too sure why its gone like this and perhaps its just me and my case.
Anyway knocked it down to 3 stars for this!.
------------------------- Original Review ------------------------------------------
As you'd expect this case fits the Sony RX100 perfectly.
Its lightweight and very easy to use.
I compared it to the Lowepro Santiago 20 Pouch for Camera - Black
which was the one I purchased originally with the camera.
Sony case vs LowPro Santiago 20 Pouch:
Nothing in it - virtually identical weight
Again almost nothing in it - virtually identical dimensions. The Sony case is a fraction smaller - but not by anything that makes a difference in the real world.
Ease of use:
Sony is a little easier to use. Flip open the front via button underneath and away you go.
LowePro - unzip and take out camera - and away you go! The only downside is you have to hold the case - with the Sony case it just flips down but stays on the camera - so one less thing to hold.
Rather sad I know but I timed how long it took to go from the case on the desk to being open and the camera ready to switch on.
Did this a good 7 or 8 times with each.
Sony takes around 6 or so seconds to get open and in a position to switch the camera on.
LowePro Santiago 20 Pouch - around 8 or 9 seconds - sometimes a bit more fumbling getting the camera out.
So not a massive difference but the Sony case is a little quicker and easier to go from closed to camera ready for on.
LowePro around £10 on Amazon.
Sony around £60!!!!
Santiago 20 Pouch looks fine to me but I would say the Sony case is the better looking of the two. Looks more like a camera case.
Short of putting my camera in the cases and throwing it against a wall its hard to test this. My feeling is the LowePro case would provide a little more protection as it fully seals the camera in a semi rigid case. The Sony case mostly seals the camera - with some gaps and has some limited padding. If protection from harsh environments is important the LowePro case would win. LowePro case more likely to protect from rain too - though its not waterproof so only protection from a brief light shower.
Having said that probably easier to drop the camera while getting it out the LowePro case. I keep the strap on the camera and make sure I have firm hold of the strap before removing the RX100 from the LowePro case.
The Sony case is very nice - less protection but still sufficient for most situations. Slightly easier to use and nicer looking - but very, very expensive compared to the LowePro case.