Hey, the thread came back online ...
FWIW, the J-frame I decided to take with me during an out-of-state trip (just got back) under LEOSA was my M&P 340. The one with the ILS. Not either of my 642-1's, my 649-4 or my 37-2, none of which have ILS's.
Why? Because the front night sight & U-shaped rear notch on the M&P give me a noticeable edge in aimed fire when I take time to catch a sight. Handy.
I have another M&P 340 on order, coincidentally enough, this time the new model variation made without a ILS.
Why? Because they finally made one without the ILS and I liked my first one so well I was waiting for an excuse to buy a second one.
Why not one without the ILS?
I'll keep my original one for use in a backup role to the new one (once the new one proves itself functional) and to use as a "range beater", to see if I can ever wear it out. While I do occasionally use .357 Magnum loads for practice & quals, I mostly use a mix of various +P (at least 4 loads I can think of off the top of my head) and standard pressure loads (budget practice).
BTW, I've experienced ... and had other folks bring to me ... revolvers, including S&W J-frames (with & without the ILS) which have had the hammer, trigger or cylinder "lock up", seize, etc. There are other mechanical (and owner-induced) things that can happen with a revolver which can cause such a problem, even in models without a ILS.