I think the QS rulers are the best, too. Their non-slip feature has saved me lots of aggravation. If they weren't so expensive I'd replace all my others. The ones I have and use almost exclusively are 3 x 12 , 3 x 18 and 6 x 24. I don't do a lot of piecing or I would get more. Well worth the price.
I put a shower handle on the 6 x 24 and I like that, too. It's the one I use most.