I think 3 are enough at the MAX. for a signature as you would've want the page to be longer than it has to
I love userbars, one of my fun projects to do. Especially animated ones. Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/532.0 (KHTML, like Gecko) Chrome/3.0.195.38 Safari/532.0
i dont have any but would love some Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.7) Gecko/20091221 Firefox/3.5.7 (.NET CLR 3.5.30729)
Userbars are outdated and shouldn't be used anymore. They were a trend that has come and gone. Honestly, with all the forums I've been on in the last two years, I haven' seen one userbar.
I only have one or two, I don't use them much because I prefer the bigger signatures, but they are not bad.
I think user bars are pretty interesting to use, although I don't use them often. sometimes in a forum I'm helping as a staff, we need to have a user bar on our signature. it looks nice, but I don't think it's a must. ^^