I honestly think that concordances are an artifact of a time past, and really quite unnecessary now. To be absolutely clear, concordances never aided the understanding of the underlying language, or not much at least. The men of the past who painstakingly made these books were remarkable, I can't even imagine the effort involved. However, computers are simply much, much better at that kind of thing.
Sites like Blue Letter Bible provide all the functionality of a concordance in a much easier, more useable form, and also link in much more useful data. For example, Youngs and Strongs give the meaning of various original language words in summary form (or so I remember, it is years since I have used either), but blue letter bible links directly back to the original language lexicon entries, which are far deeper.
Really, copyright aside, all bible students should be able to fit their creaking old bookshelves of concordances, grammars, versions, critical apparatuses, commentaries and so forth onto their one pound kindle. I like old books. There is a certain tactile pleasure they bring. But they simply aren't as functional as their electronic equivalents.
There are few things and changes in the world that are an unadulterated good, in the world, but this is one of them. Kudos to the folks at blueletterbible.
