I've used SE a bunch before but I recently bought VST Connect Pro.
I'm finding that the Studio Pass app is pretty poor on the client's side.
- The front camera on my iPhone 6s Plus just shows green lines (camera works fine normally)
- The audio comes out the phone speaker up the top of the phone (so you have to hold it to your ear) by default.
- The aspect ratio of the studio's video is squashed
This is the main reason I bought the Pro version - so that people can listen to mixes with their iOS device wherever they are.