+1. The animation times on the ST attacks are not kind, but Rad is top tier for AoE. Shield/rad would be my pick for a min/max Tank. I would lean more towards doing one, but I have the Scrapper version, and I'm kind of done with Rad's animations in terms of wanting to level another one.
Options not mentioned, Shield with Elec or Savage as both give you tele nukes although both are lacking in ST damage. I still think Savage is what Claws should have been. I made a Rad/bio Brute and that certainly makes me wonder what a Tank version would be like because it is going to pump out a lot of orange numbers. Any tank with two damage auras is going to wreck things. Balanced versus AoE heavy, but the smoothest set due to animation times unless I missed something is StJ. The more I play other sets the more I want to play StJ instead. I find EM more on the good side than fun, but Dark/em would be great for stacked stuns. Don't get me wrong, EM's ST damage is incredibly good maybe too good, but any time you have to deal with TF's animation time it raises an issue for me in the fun factor.