I have used recount since I can remember, it is true that skada has improved a lot, skada in WotLK was a pile of garbage, and in cata is was just bad. Maybe it is on-par or even better than recount now, I do not know. Atleast when I tried it I could not get proper functions out of it.
Of course WoL is the best for in-depth analysis. We always viewed recount as a light weight in-game WoL. Recount suffices for quick check ups between pulls, stuff you can check while corpserunning, while WoL calls for some more time spent analyzing the data. Using both will yield the best result.
What can you track with skada that recount does not track?
Some issues I had with Skada (those that I can remember atleast, know I had more)
Did not track as many fights as I want it to.
Could not track ungrouped players
No tracking for monsters that are neither hostile,neutral or friendly (a.k.a. mobs with no target/bars etc)
Much worse pet tracking
Much worse boss damage done/taken tracking
Much worse add damage done/taken tracking
No tracking at all for fire on the ground
No death logs for adds, only for players
I do not know how many of these things can be fixed with settings, I am by no means an adept skada user and I tried asking some players but honestly, 99% of players using either recount/skada does not know how to fully utilize them, so was probably asking the wrong people about it.