Just curious, For those of you who have both, is the knurled screw on the bottom better/nicer than the hex screw? It just seems it would be one less piece to get lost. On the other hand it might be more likely to come out when you did not want it too. Any experience?

I also wonder if you could drill out the bottom of one of the plastic ones and put a little bolt in there just like on these? It might be worth a try if you had one that was used up. They are pretty thin so it might weaken them too much.