ECS and sturdy are not exactly two things that go in the same sentence most times. There are a few exceptions here and there like with some of the old K7S5As. I had one of those folding for years and my mom still has one running in her system which is still going strong. However, I generally avoid them as the initial money saved will normally be eaten up later on by something going wrong with the board. I prefer to spend a bit more on a better brand for peace of mind.
I've got a buddy that got a 945 chipset ECS board for free with his E2200 from a fry's combo. He HATES the board and its lack of features, but the price was right and he hasn't had any issues for stability. He does want to get into a P35 board though at some point.
A while back when I posted about the BSEL mod with tape (still can't believe it's that easy) I read a thread where the guy had one of the ECS G31's and it took the mod fine.
That said I keep saying I won't buy another ECS, and like a drunk, keep on buying them. Mainly because I get the combo's at Fry's or Newegg when the combo price is less than the best deal I can get on the CPU alone.
The last three ECS's I've bought have been stable but absolutely no OC. As soon as one gives me problem's I'll replace it with a $50 m/b.
By the way - Fry's has the Q6600 for $189 B&M, time for an upgrade!!