They are banned on some sites because of a perceived lack of ankle support and they are not good for climbing ladders.
I know some people (including me) find them a bit awkward to wear at first because the hard overlocked seam of jeans rub against their ankles. I immediately found that wearing Regatta-type work trousers, chinos, normal trousers or track suit bottoms resolved any problems. I now find riggers really comfortable to wear.
Either way, they are warmer and more comfy than wellies to wear in snow
When i was a tower crane driver/erector i used to wear rigger boots. Never had a problem climbing vertical ladders. I used to love them for working in.