
You are basically getting 200ed runeword (so can be preupgraded for more %ed than unique with jahs total), and 300 damage added, skills and spell proc.
It isn't bad at all.
Depends on stage of your gear, spell proc is just carried by its level and that pierce. Besides that pierce should help our thunderfury proc from axe, but thats about it (rest of damage is physical & cold). I think further you push the character, your phys damage goes up and spell proc becomes less and less relevant, as we don't have enough spell damage scaling on this build.
But im not sure, I might be just as well underestimating power of level 60 forked lightning.
Even without it it would be decent axe, basically a good craft without crafting. Problem is farming those runes if you played solo self found, it would be faster to craft something.