Wow, some people just LOVE to misunderstand. 
I’m sorry but you can’t have VST plugins always on top of the MixConsole in Cubase 7.5. You are talking about leaving parts of the screen blank. That is not a solution, sure it’s sort of a workaround if you keep the MixConsole GUI really tiny and minimize all insert chains etc. I guess Rhino is talking about the same thing here.
The thing is that the new MixConsole is LARGE and it needs to take the most part of one the screens. It doesn’t matter if we set it to full screen mode or not - VST plugins WILL disappear behind the mixer when you touch the mixer!
One other thing: Cubase doesn’t have a key command for “set focus”, so alot of Key Commands doesn’t work when you have your VST plugin in focus and then want to change something in the MixConsole with a key command. Sure, I can get a third screen, but I’m not an elite professional with a large studio so I don’t have the space. 
I have also been using Cubase for 14 years (started with Cubase VST32). But we are talking about Cubase 7.5 here, right? Maybe you haven’t notied that the MixConsole is a bit larger than the old mixer so leaving empty screen space is not an option for us that only have standard 24" screens and still wants the MixConsole to show its potentional.