Skithiryx is a little lower on the power scale, only being a 4/4 for five damage, but it more than compensates for the lower stat line with its abilities
These cards have not been legal in Commander for a long time (originally being banned between 2005 and 2009), and a lot has changed in both Magic and Commander since
In my preview column on the design of Dimir, I explained why grind (the "mill until you hit some number of lands" mechanic) wasn't the named mechanic of Dimir
The latter is the more common
I find myself again echoing the words of Neale Talbot and his Seven by Nine theory, even if were not intending on building a singular deck this week
Given the faster openings of many decks these days, and the importance of being proactive with your early game plays, having a free removal spell is huge, and I think it should see more play than it does