I was brain-farting after a long day at work and I just couldn't get the Relay rooted using Odin. Switched ports, different cables, CWM, TWRP, side-load whatever .... towelroot got me rooted in two minutes. Would have been 1 minute but I didn't open it after downloading, so I had to do it again to "make it rain".
Of course, then I found out I was not entering download mode correctly using home key+vol down key+pwr key - guess I was so used to hold both vol up and vol down at same time on other phone. So .... didn't need it in the long run, but saved me some time and I donated to developer as well.