Sneakylong I would say that anyone who gripes about gapping really hasn't taken the time to play SL and get to "know them." I played them for a few years and my iron distances were very similar to my traditional set. I did gain a few yards in my short irons and lost a couple (if that) in my long irons. But the differences were really small.
I'm also not sure, Sneaky, that these clubs don't make sense for you. I think there is a misconception that the strength of SL irons is that they make it easier to hit the long irons. I don't believe that's their strength. Even if people could swing their long irons more consistently, the 3-iron still has a 19 degree loft and the 4-iron a 23 degree loft (I'm speaking of the 1Irons here). Most people do not have the swing speed to hit those lofts consistently and get their yardage gaps from them. Enter the hybrids. So, most people are talking 5-iron and up.
So, why hit SL. Consistency. Consistency of feel, consistency of set-up, consistency of swing. And the same thing can be said for the short-irons. I have preached this for years and argued with the "we-need-shorter-irons-to-be-shorter-in-length-for-accuracy people" that shorter lengths do not mean accuracy. The fact for me, and I have heard this over and over from new SL users, is that once I got used to the SL short-irons, they became my favorite part of the set. I quit playing SL irons a few years back and now play Wishon 560mc, BUT my 1Iron wedges, GW, SW, LW, are still in my bag.