Im not a professional builder by any stretch. In fact, being a hobbyist may be a stretch! lol
I will say that since i have gotten mine, my game has gotten a lot simpler. Its not easier, its not point and shoot, but plain and simple, its so much simpler to grab a club and not worry about how the swing arc changes from club to club.
Best way i can explain it. If i walk up and hit a great 7 iron, with regular clubs i may have to wait 2, 3, 4 more holes before im in position to use a 7 iron again. In the meantime, ive taken at least 6 swings (or more....) with different length clubs and lost all feeling i have of that pured 7 iron.
With SL irons, i can know that the swing i just hit that 7 iron with, is the same one i hit the 5 with, the same one i hit the wedge with, i feel like i can take that same swing all over the course, and adjust either my grip for direction or adjust my backswing for distance. For me, it makes it so much quicker to get into a groove, and removes some very bad swings because i didnt have the right arc for an 5 iron on hole 3 after hitting a brilliant 9 iron on the previous hole.
Im stressing again, it does not make golf easier. My first outing, i shot 3 strokes better than i did in 2015. I still hit fat, skulled a few, ganked putts, etc. What i feel it did do, was make it a lot easier for me to get into a groove, and not fall out of a groove as easy. Im a feel player anyways, so being able to use one swing, and just adjust my backswing accordinly for distance is something very exciting to me. As is practicing my 4 iron thru my wedges always using the same swing and feeling. Hope this helps