I'm unconvinced that the "client pays legal fees" clause is really a sure thing. All the client has to do is make the argument on some other basis, and suddenly it's not a collections issue but a dispute over something else in the contract. In most states, each side will pay their own legal freight in such civil complaints.
I've personally been on the wrong side of it with some opportunistic a-hole lawyers and a 30-day late payment on my condo fees. Maybe it wouldn't have held up if I wanted to dump 5 figures to fight it all the way, but then that's the point, right? Once you threaten someone with legal fees, they're likely to get a lot more cooperative. Personally, I ate it rather than fight it.
