I decided to go ahead and get some of the 5 cent bills. I ended up getting 10 bricks to try out at my next game. When I first got them, I couldn't believe how good they look and feel. These are the best 'play' money I have ever seen.
After seeing the front of the bill, the back was a little disappointing. The graphic choice makes it look less like a real bill versus the front. I would have preferred an image similar to the back of the 25 cent bill. I don't think it matters much because the front of the stack will be visible most of the time in my games. I also wondered how I would store these bills and found that an empty check book fits the bill nicely.
The only other complaint I have is that I don't have more money to buy a bunch of them.
I will probably be buying some 25 cent bricks in the future. My small 5/10 cent games never get big enough to use those 25 cent bricks, but maybe one day they will.