Mid control, especially late mid control, is really good
on offense, peek mid from sewer side (statistically better)
if you go mid from both sides, sewer side should peek first
retakes are easy if you have Raze grenade and/or spike is planted badly (hidden, not visible from heaven)
on the other hand, if you can plant spike for heaven and you maintain heaven control, it's really hard for them to retake/defuse