As for being Meta-efficient, I think Mr. Whitecr0w says it best in his guide: " Shaco is a FUN, worth, powerful Champion. Is he a carry? No. Is he an initiator? No. Is he a tank? No. Is he a support? No. Is he a burster like an AP mid? No. Is he an assassin like Kha'Zix? Kinda. Is he a bruiser that can help tank to initiate? No. [...] Shaco is what we know as an anti-meta, and you will be soooo busy when playing with him. He has two main objectives: to Deny and Demotivate your enemies and make your team rich. While he is not the best fighter or assassin, he has epicly good utility."
Perhaps Mr. Whitecr0w, Psiguard or somebody with more jungle experience than I can give a more insightful answer as to why Shaco's popularity is where it is (all I imagine is he's not chosen often because he's got a high skill floor, and his kit isn't necessarily intuitive). All I know for sure is that out of the 31 "normal" junglers, Shaco (chosen in 1.5% of games) is the 15th in popularity; chosen about half as often as Kha'Zix.
Well, Shaco is a pretty difficult jungler too play. so it'd make sense you're not seeing him much at lower elos. Everything i've heard about Shaco says that he's hard, which will detour less skilled players who will then go on to player easier junglers like Warwick and Rammus.
As for being Meta-efficient, I think Mr. Whitecr0w says it best in his guide: " Shaco is a FUN, worth, powerful Champion. Is he a carry? No. Is he an initiator? No. Is he a tank? No. Is he a support? No. Is he a burster like an AP mid? No. Is he an assassin like Kha'Zix? Kinda. Is he a bruiser that can help tank to initiate? No. [...] Shaco is what we know as an anti-meta, and you will be soooo busy when playing with him. He has two main objectives: to Deny and Demotivate your enemies and make your team rich. While he is not the best fighter or assassin, he has epicly good utility."
Perhaps Mr. Whitecr0w, Psiguard or somebody with more jungle experience than I can give a more insightful answer as to why Shaco's popularity is where it is (all I imagine is he's not chosen often because he's got a high skill floor, and his kit isn't necessarily intuitive). All I know for sure is that out of the 31 "normal" junglers, Shaco (chosen in 1.5% of games) is the 15th in popularity; chosen about half as often as Kha'Zix.
oh, sorry, thats twitch.