Relying on IDEs to give you insight into what should be obvious by just looking at the code show's that something's wrong IMO.
I used to really be anal on making every single line explicit: no shortcuts. But over time, especially with increasing my usage of templates, I've come to relax on these things and prefer to put my efforts in good variable names and trusting the compiler.
I'm not saying you should use auto for basic types (especially ones that can be easily cast into each other - that shit gets dangerous). I am saying that auto is extremely powerful when working with most interesting APIs. The most recent example I have is a lot of things I end up doing with chrono.
Sounds like there's an opportunity for better diff tools.
If I'm not going to depend on the IDE to tell me what a deduced variable type is, you can bet your ass I'm going to want to depend on it for autocompleting some of the insanely long type names are: std::chrono::steady_clock::time_point gets old real quick - and so does stead_clock::time_point (if you want to include the namespace).
With regard to the hovering issue specifically, there can be a great deal of visual clutter from type names that is a hinderance to understanding most of the time; now you only have to see it when you need it. That is only the start, however; a decent IDE should, for example, make it easy to go from there to the declaration of the type, should you want to.