I have had all 3 of them and they all have their good and bad points:
-- 3.6L GM in a 2008 Acadia with 275 HP@6600RPM and 251 LB-FT@3200RPM
-- 3.5L Ford in a 2014 Ford Explorer (First Gen of the 3.7L) with 290 HP@6500RPM and 255 LB-FT@4000RPM
-- 3.6L Pentastar in a 2019 Jeep with 285 HP@6400RPM and 260 LB-FT@4800RPM
The GM required a water pump change at 76,000 miles, but otherwise had no issues with it. It was not very powerful and gas mileage in the Acadia barely cracked 20MPG, I put 100K miles on it before selling and perhaps just prior to the timing chain issues rearing its head as so many have experienced. I ran Pennzoil Platinum 5W-30 and AC filters in it the whole time I had it.
The Ford required the secondary throttle body to be changed twice and there were a few sensors and emissions components that had to be changed, but otherwise no issues. It typically sees 23-24MPG on the highway and is satisfactory in the power department. The sparkplugs and COP boots were changed at about 80K and it was time as the engine ran decidedly smoother afterwards. It has had Mobil 1 AFE 0W-20 and FRAM Ultra filters for the majority of its nearly 100K miles. I did use a few Motorcraft FL-500s filters and couple of runs of Kendall GT-1 0W-20 in its early days.
The FCA is still quite new with only 12K miles on it and no issues to date. It has enough power and runs quite smoothly and manages 21-23MPG on the highway at speeds up to 70MPH (MPG drops off after that).There are some pitfalls in the first generation engines with head and valvetrain issues, but that has been resolved in the Gen II series. However, the oil filter housing/oil cooler is still prone to cracking by over zealous wrench turners. FCA should have taken a lesson from MB and made the entire housing from aluminum instead of 50/50 plastic and aluminum. It has had Castrol Edge 0W-20 and Mopar/Mahle/Hastings/FRAM Ultra (the Ultra is the choice going forward) filters in it.
From my experience thus far, I give the "win" to the Pentastar for its smoothness, power range, and economy. It has the start/stop system that so many despise, but it does save on MPG while in the city. Time will tell how it fares, but I would surmise that it will do well when compared to the millions of other Gen 2 and Gen 1 engines on the road.