I've never seen one in the flesh, but there was one in the PH classifieds for ages a few years back. Was sat there for months not too far from me and at quite an affordable price. I was a little tempted.
Can't see the pics in your post, but yes, I have seen a Bitter. Drove one for over 30,000 miles in fact. Just sold it a couple of months ago. Great car, good to drive, very practical to use every day as I did.
Looks nice, and good to see in regular use. Non-standard wheels. There's a very active group from the Netherlands and Belgium in the Bitter Owners' Club, who are a great bunch of enthusiastic owners.