I do transmit with it, with very good results.
As far as measurements go, this is what I used.
http://www.m0ukd.com/Calculators/Slim_Jim/
I used 465 as the frequency (median between simplex and repeater inputs).
It's all type M copper pipe and standard elbows.
If I were to do it over I would use the same measurements but instead of measuring center to center on the copper pipe, I would measure the distances between the closest edges of the pipes. I found the feedpoint measurement from the calculator to be way off from acceptable swr; this could be from the center to center measurements, or the de-tuning of the antenna by adjacent metal in my attic.
Scuffing up the pipe with sandpaper helped make a better connection at the feed points under the hose clamps.