Define early game. Is it your first item? That's 2200 Gold for three crits with no AD behind it. The Attack Speed is shut off while the item is on cooldown. So we're looking at 2200 Gold for +145% ASPD for 3 crits, no stats at all when down. Compare this to a laner that went Doran's + BF Sword instead. 55 AD is roughly a 50% boost to your base AD anyway, effectively getting you a better damage per gold spent ratio and with less downtime. And the +Crit% of the item gets worse, gold efficiency wise, as you get more base Crit% as well.
In a perfect world, SotD makes some sense in a full build as it gives them the potential to completely remove one character from a fight practically instantly. The question becomes when do you get it. Before IE? PD? BT? GA? LW? RH*? What about Zephyr for the AD/ASPD/CDR/Movement? Statikk Shiv for the proc that crits (and charges build up when using gap closers like Tumble)? That's basically where I'm thinking on it from: When would you even get this item?
The stats of SotD make the most sense for someone with a massive amount of AD and minimal ASPD/Crit% that wants to convert that to more damage (e.g., 400 AD Zed becomes ~2040 pre-Armor damage), not someone that has AD/ASPD/Crit% anyway. At least, that's the way I see it. That said, there probably will be kill lane setups where you could get it first to try and make magic happen (Blitzcrank, Leona) with the sudden burst. But, generally speaking, it's more meant for AD Assassins.
On that note, Zed and Fiora may be the two best SotD users if only for the AD%/flat AD built in their kits to let them get to higher AD values with less items. Basically, Fiora can get away with a Mercurial Scimitar + SotD build. Lunge in, Burst of Speed + SotD to melt a carry, Ult someone else, pop Mercurial to get out (if not needed to Cleanse a CC on the engage). If fed, you can add Tiamat/Hydra into that to even get some splash in there, though LW or Cleaver would probably be better. Gives her a legitimate reason to look at 19/11 or 21/9 instead of 9/21 (which would be more of a BT + BotRK + Tiamat/Hydra setup).
Regardless, I'm looking forward to all the experimenting to be done. Should be good times, even if I'll just play the same champ every game anyway.
*Why do both Ravenous Hydra and Runaan's Hurricane share this acronym? >>
say 12-23 minutes where I got a bt and zeal in to pd setup may not be what I want. BT and SOTD will be decent damage. I rarely think of gold like that unless I have too I think of potential. 3 crits with that as plus my other steriods is huge that turns a maybe half health or 75% in to a sure thing. No other item can give me that with a bt at that point.