Bought from 6pm, boots actually shipped from Amazon so I'm putting my review here.  These Sarnia boots are very nice looking, though the 'Espresso' is definitely a dark brown rather than the reddish-brown pictured on Amazon and 6pm.

Now for the important part: the arch support in these boots is the lowest, weakest arch support of ANY Birkenstock product I've ever tried.  The insoles may be 'genuine Birkenstock cork footbeds', but they are nothing whatsoever like the Original Birkenstock Footbed.  I understand that they had to make allowances so that a person could get their foot inside the boot, but a full length zipper and good arch support would have been a much better way to go than putting a zipper in the middle of the shaft of the boot.  Honestly, why bother with a zipper at all in this case?  The shaft of the boot is plenty wide to allow the boot to slip on with minimal effort (slide the foot into the boot as far as it will go, then pull up on the back of the boot so that the foot slips the rest of the way in).  At least the metatarsal support is good, so I'll give 3 stars for that.