I've been wearing Altama OTB for a while now and find them very comfy. I've never worn Cons but have read these are like a hardcore version. Designed for military swimmers apparently which is why there's the camo versions (I assume). Having a rubber insole they can get a little hot but lots of people have swapped them out for other insoles.
Link to the UK stockist (a little pricey but seem to hold up well in my experience).