In your guys opinion, I found on Amazon bar clamp ends by Irwin, they sell them in 1/2 and 3/4 inch sizes. Is there a noticeable difference in either one, does the 1/2 have enough flex for a 6 foot clamp to be an issue? Does anyone have the Irwin ones and does not like them, should I get grizzly or pony? At this point I am jointing boards to make a 27" shelf. Figured I may as well go ahead and get the 6 foot pipe, trying to save money where I can. Any advice you guys have for me would be greatly appreciated.