Hi Tom
Only started wearing them last week as i ordered wrong size and had to send back for another pair.
Yes these boots are very comfy and very light (as comfy as any trainers i've worn) the insoles on them are pretty thick and can be replaced with news ones when the others are worn, also find feet don't sweat in them but still stay warm.
As for waterproof i haven't really worn them in heavy rain or anything but working in customers lawns (long wet grass after its rained etc) for lengths of time my feet have been bone dry (i did put a bit of dubbing on them too). Also the soles on these, tread etc is very good and can see them lasting a while.
Overall very pleased with them and can see them lasting a long time i've only ever bought boots that are around the £60-£70 mark rockport etc and would say these are better and a lot more comfy.
Even if your order from BRIX workwear and don't like them they will take them back without any hassle, they can be a bit cheaper elsewhere but brix do lots of discount offers every week (i got 25% of mine at the time of ordering).
Paul