Lionheart is a good but not great armor. Mr. LLama puts it in his upper B-tier and I would agree with him. Its not to expensive, offers okaisch mods but you might not find the runes on your normal playthrough and to make it on purpose later might be only an option for some players (have made one, played a bit but did not really love it to much).
But, I could see ED beeing buffed a little bit. But not ot 100%-200% (would result a cheap forti alternative).
So 50%ED or even 75% could work…but on the other hand. Imho no need to buff RWs before they work on uniques…