How wide are you going? I did my X-Men one then went back to Spider-Man, but I'm thinking of going full hardcore, within reason. Tempted to stick to the core titles (FF, Avengers and their separate books), but I could be tempted by Doc Strange and whatever else...I'm just slowly working through the Travis Starnes reading order for 616. It covers all the main characters (Spiderman, X-Men, Avengers, Captain Marvel etc) and throws in the more important issues of stuff like Guardians of the Galaxy debuting in Marvel Super Heroes.
I am noticing gaps appearing more often though, mainly in smaller titles like Daredevil, Sub Mariner and Nick Fury.