Right out of the box - I knew these would be great. My pair was sized about 1/4 size small - so I had no problem going up 1/2 size to 9.5 D (M). These were purchased for use  on a specific military training site (Fort Hunter-Liggett, CA) where I'm assigned for the summer as a computer support contractor.

These work great for long hours of instruction on a concrete floor as well as access to unimproved training sites. I'm a 27 year army veteran/retiree with flat feet (contracting for 13 years now also) and tend to pronate while walking - these work well for me without foot pads or other orthodics. Went through mud, dust, heat, rain and cool nights without foot discomfort. My feet remain dry in amost all conditions (these are not waterproof as they have vent holes near the center side arch support) from the inside as these boots breathe and ventilate well.

The zippered sides gets me some razzing from fellow vet contractors - but sliding into them in early morning getaways to the worksite is appreciated (I understand 5.11 will come out with similar zipperless models in August 2011).

Mud is always a problem no matter what you wear - and indeed these slide around as the boot sole lugs fill up as all boots do and are not as high as combat boots so be careful how deep you step into mud. The padded upper ankle support needs to be lace adjusted as not to be too tight (or loose) and after less than one days wear these were broke in and I love them. My favorites however are still my black Danner Fort Lewis 'go-devil' boots purchased over 20 years ago with plastic heel cups and goretex lining (one pair also insulated) - (almost wore out both pair) but these aren't needed in a computer or headquarters environment where I work).

Imported from China - they tend to be a little expensive for where they're made - but for my environment where taller boots aren't needed - these work for me very well indeed. How well they wear is unknown - the materials seem to be first rate. We'll see!