As a Zed main, works for me. People talk about Zed ult and zhonyas being on different cool downs like it actually matters. It only matters in a perfect game when you are in position to ult right as your ult comes off CD every time. Otherwise, chances are, zhonyas and your ult will be up together so the reduced CD really isn't much.
Zed is in the perfect spot to hit 40% CDR every time so even with a 15% reduced zhonyas, he'll still easily be able to ult later in the game without always being zhonya'd.
Plus maybe mages will stop bitching about hexdrinker.