I also bought a Hayden HD fan clutch and that thing was engaged 90% of the time. After 15 miles at 70mph, it would finally kick off as soon as I came to a light or stop sign, it was engaged again. It drove me absolutely crazy.
I overheated in a parade on the 4th of July and vowed that would never happen again. Out came that wimpy, yet somehow OEM, 5 blade fan and fan clutch that resembled a CD. Out came my OEM radiator, which while adequate was extraordinarily dirty and, well, 30 years old.
I wanted to keep my Mopar all Mopar, but I couldn't find a Mopar 7-blade fan for under $150, which is just dumb.
I bought a high-quality all-aluminum radiator, new belts, a Hayden 6-blade fan and a that heavy-duty Hayden clutch...and you're right, it might as well not be on there at all because it's ALWAYS engaged, which is fine for me because it keeps my car nice and cool and keeps the AC blowing cold even at idle, in gear, in parades.
As far as aftermarket stuff being hit & miss, I have found in this particular case the Hayden HD clutch and Hayden 6-blade fan to be of VERY impressive quality, much sturdier and heavier than the OEM stuff I took out. It's performed flawlessly. As far as I'm concerned, everything I did was a massive upgrade over OEM, and not having all-Mopar stuff under the hood is a concession I'm willing to make to avoid even the slightest chance of overheating.