also to what Joe said, I doubt fitness is back sliding, though performance may be .. but that would simply be related to fatigue & adapting to more frequent runs & overall higher intensity etc. that "accumulated fatigue" effect works for running too -> you can run yourself into the ground a bit then rebound out hard by cutting intensity/volume and/or resting more etc.. so in that case, fitness is improving in the face of that decreased performance, just takes some tapering/sharpening/deloading sometimes to express it.
I wouldn't worry about it too much, adapting can be taxing.
and to what you said at the end: I love hardly looking at my watch when i'm running easy. Looking at the watch will almost always make you run faster.. for easy runs, it's great to just look at the duration and/or mileage and just relax. "harder" easy runs may need the watch, but true easy runs, can just go coast and relax.
and ya, hard on hard days! can only do that ~2-3x/wk, leaning more towards 2x .. even 1x is necessary occasionally when you just get run down.
finally, every day is different. I can run great on tuesday of this week, and crap on tuesday of next week. ride teh fluctuation waves!
pc!!