I have played many rounds with a set I made out of conventional Wishon 752TC heads. I converted them all to 271 grams and 62* lie angle. The gapping is good, at 10 yards. But, I customized the lofts to get that right. The 5 iron can be a little on the low side. Because of that, I go back and forth on my feelings about the 5 iron. It's so easy to hit that I have chosen to stick with it.
When I first tried an SL set several years ago, I did have mental problems with the 5 and 6 irons. But not with this set. In fact I love hitting them because I have so much more confidence in them at 37 inches.
Wedges can go higher and farther than expected. But mine are pretty good. I have no problem playing the ball back slightly with wedges and up slightly with the 5 or 6. You don't have to use ONE ball position any more than you do with a regular wedge or 6 iron. In fact, once you learn a different shot with one of these irons, you've learned it with all of them! That is a big, fun deal in my mind.
To the other question about the 4 hybrid length. At that point I am playing conventional length clubs. You have to have club head speed to get low loft clubs to fly high and far enough. So, I look at my irons as scoring clubs. I look at the hybrids and fairway woods as the compromise they are. They need to fly a certain, long distance with good height, and I have to be willing to risk the miss that comes with them.
Also, my SL set only goes down to a 52 gap wedge. My 58 wedge is a conventional full weight 35" club. I have a 58* wedge head that I might someday convert to the SL set, but it's not a priority. (I have no idea why the words "gap wedge" are italicized above. I did not do it. ??