Overshoes are warm (not waterproof) and work better than Shimano GTX Hiking boots / ‘original’ shimano winter boots (mw80 predecessors) and generally warmer than sealskinz.
The downsides are that the toes peel off after walking around and they can suffer after walking around, therefore cheaper is better (think neoprene)as they’ll only wear out.
I’d go for insulating material (i.e. Neoprene) as opposed to waterproof. I don’t think waterproof shoes really do that much riding through puddles and rain all the time
The ‘solid black’ neoprene jobbies do look odd, but then these things are all relative – to all normal people we look odd, but fashions in cycling mean the ‘trendy’ look just makes us look less odd than others. I imagine the MT 500’s probably look less like ‘Lego boots’ than neoprene ones.
I can’t afford new winter boots ATM, I’m going to try and get by on just ‘thermal’ sealskinz and overshoes.