I am fixated on carrying AIWB for safety, concealability, speed and comfort. I assume the Supertuck is a behind the hip holster. My comments may not apply.
I am 5’ 11” @ 185# and carry the standard 4.25” full size 9mm M&P with an aftermarket Apex threaded barrel. That adds a half inch (Total 4.75”). I find almost no problem carrying it AIWB on a Wilderness Tactical 1.5” belt in a good Kydex holster made for that length barrel. Only on long drives (4+ hours) do I need to either remove it for a while or at least have two good 20 minute breaks. I carry a spare 23-round mag at 10 o’clock.
Bigger guns shoot easier than smaller ones. Generally less perceived recoil and more consistent accuracy. I also like capacity for self defense.
However, I believe there is a point of diminishing returns in trying to carry larger guns concealed. Both weight and size can come into play, depending on your body size and condition, carry accessories and carry position. I know of people who claim to carry Glock 35’s AIWB. They may do it, but I doubt it is as comfortable as a shorter gun.
I personally would not buy a 5” M&P to carry anywhere concealed, but you may be different. I prefer the extended barrel with the shorter frame. It balances well, shoots great, is a little lighter, and down low in the carry position it is smaller. I also have an RMR 06 milled into my slide, so my iron sights are both tall to cowitness. If I had a 5” it would make that end of the gun even taller, taking up more space down low concealed. A longer framed gun is also harder to clear from a holster, especially if carried behind the hip.
The gun below is close, but if you are not putting on a suppressor or a red dot sight, you don’t need the taller sights. The difference between the factory 4.6” barrel and my 4.75” is neglible, except mine is gunsmith fit and will likely outshoot a factory tolerance barrel, if that matters.
M&P(R)9 M2.0™ with Threaded Barrel | Smith & Wesson