I loved this article and the question it raised I’ve been facing for the last 6-9mos. I’m not a big fan of hybrids so I marked that off the list but I have deliberated between just a traditional 3 iron, a utility iron, and a 5 wood to fill that gap. My trackman numbers are eerily close to @jon 's so that was interesting to see.
The driving iron I have is a Callaway UT 18 degree as compared to my stock Callaway Apex Pro 3 iron and a Ping G400 17 degree fairway wood. Off the tee, I love the driving iron quite a bit-- it’s a great fairway finder and I have smaller lateral displacement. As compared to a traditional 3 iron, it’s a bit more forgiving off the tee and assuming I’m not trying to clear water, a thin shot rolls out far enough to get the job done. The fairway wood is close second off the tee but my lateral dispersion is greater and when I error, I tend to spin it too much right to left. This makes for tight tree-lined fairways where there isn’t much room on the right side to start the ball.
Hitting off the deck, I find the fairway wood substantially more reliable. My angle of attack is steep and the UT iron just doesn’t feel quite as good as a traditional 3 iron. I’m sure it’s more mental than anything else, but assuming i strike it well, the 3 iron just feels crisper and when I don’t, the extra bounce of the UT iron is not always helpful. I find that when it comes to holding greens, my fairway wood lands softer and higher, a well struck 3 iron has more bite, and the UT iron falls somewhere in between neither landing softer or biting harder than the alternatives. Perhaps I’d feel differently if I had a higher lofted UT iron but I think my willingness to experiment with UT irons is waning.
All that being said, my standard set is now a fairway wood as a good compromise. If I know I’m going to a course that requires a lot of tight, shorter fairways, I’d consider bringing the UT iron that could be used almost exclusively off the tee. If I know I’m going to experience hurricane force winds, I might consider a traditional 3 iron all else being equal.