A somewhat important point to be added: there is a difference between Sportingbet.com and the sportingbet group. The sportingbet group is a very large collection of books - with huge differences between them.
Sportingbet.com is probably the best of them. They're pretty much okay (except for the things noted in that linked thread). Sportsbook.com on the other hand is a sportingbet book which is on my personal DO NOT TOUCH list due to many complaints which I have monitored literally for years. And there is everything in between.
I could tell a bunch of stories about a bunch of different sportingbet books, but I think I would sum it up this way: never assume because a book is part of this group that that means anything. They all seem to do their own thing. These books like to advertise how they are part of a publicly traded group, but they are not supported by head office at all if the sh*t hits the fan.
Assess them on a case-by-case basis.