Yeah, a little more "advanced", that's true... The idea is, as you stated, that you spend your time on the actual recipe and not on entering in all the same flavor names each and every time, plus drops per ml, densities, pg/vg ratios and standard percentages etc.... Of course it does take some extra time initially, but that's a one time thing mostly which pays off in spades later... Then you also have a nice overlook over your stash and can see how many ml's e.g. left of each flavor, vg/pg and nic and/or to alarm you when reaching under a specific threshold etc. The calc part itself also can display/behave in different ways according to defined settings.
The above, is a few highlights among the things why I stated it to be the more "advanced" counterpart to ejuicemeup... Again, I don't use it myself, but just really impressed by it... (I don't use it because I have no use for all those extra "bells and whistles" and so a simple spreedsheet I quickly drew up, is fine for my purposses, and also not to mention the fact that I use linux exclusivelly and dont wanna run wine)