Does anyone dislike Sion's Ult?

This is a little strange for a champion's ultimate skill. But I almost never feel the need to cast the ult, other than to quickly finish off an opponent or blitz forward like a hard to control ghost summoner. It's probably the most unreliable ult I've tried to play with so far. :/ It feels useless, and more often like something easily forgotten. I can't use it in close quarter fights like Baron. I can't rush out of base because turrets/walls are your worst enemy when trying to get out to the fight.