I know they are generally the best boots for mids but 1100 gold for 45 ms and 15 magic pen seems weak, while haunting guise gives 15 magic pen, 200 hp and 25 ap for 1485.
even like merc treads give 25MR 45 movespeed and tenacity for 1200 gold. Like sorcerer shoes need to be buffed

are you kidding ? 15 magic penetration + Mpen from runes is crazy damage.

they used to be good because it allowed you to get to full speed and get pen simultaneously, but with the changes to movespeed this season i dunno anymore...

It's still good cause of how the pen formula is. % pen then flat pen, so the 15 pen helps you get to true dmg even more.

but I haven't seen a void staff in I don't know how long, like all season

15 mpen from sorcerers boots , + mpen from runes + plus mpen from mastery , + mpen from liandrys + void staff, thats alot of penetration there sport.

Since the changes to spell pen, CDR boots can't compare any more.