RX1 EVF my findings
Some have secured their EVFS with gaffers tape. Personally I have not had much of a problem with it slipping off, but the snagging on the bag when stowing/unstowing the camera is the worst feature.
Built-in EVFs won't likely come with the nifty swivel* that I use extensively, and the view from the EVF is marvelous, and a far tradeoff with optical considering how WYSIWYG the whole experience is (DOF, color balance, exposure, etc.)
A big point in favor of the EVF is how much more natural and steady it is to shoot with the camera braced against you. Shooting with a non-articulating LCD is very unnatural and unstable.
*Minolta actually did once have a swivelling built-in viewfinder.