Looking at 2016 Jeep Grand Cherokee with a diesel or 2016 Infinity QX50- most reliable??

From the choices you listed I would be between the GMC 1500 and the Jeep GC. Truck or SUV... SUV-wise you are going to have a hard time finding a better jack of all trades than the current Grand Cherokee (maybe I am a bit biased as an early WK2 adopter). Great road trip car, suprisingly capable off road, but able to take clients/wife out, or park with the valet without being emabrassed.

They have worked out a lot of the issues in the earlier models (first gen QL air suspension, early 8 speed trans) The diesel option certainly gives it the lead for range and mileage compared to the truck or other options. The Grand Cherokee is also a very capable tow vehicle, tho limited in capacity slightly to the GMC. but, boy those GMC's have come a long way as far as interior and panel fitment.

We are actually looking at the same two options (GMC 1500 4x4 and a new Grand Cherokee Overland diesel) So far it has boiled down to "do we need the utility of a truck bed"... and since i have a large trailer I really dont. So we hope to be seeing a new Wk2 in the driveway soon. I would definitely suggest the mopar lifetime extended warranty if you get air suspension on your Grand (not normally a warranty guy, but it has more than paid for itself 2 or 3 times over already).I do know of a few 2014 2015 owners that had transmission issues just past OEM warranty, again the lifetime warranty was a savior. The warranty claims/defects dont seem to be excessive, but can be quite costly without it. It will be tough to get a new model with QDII and either the Hemi or the Diesel, without getting QL air suspension, but can be done if you go new 2015 or a 2016 limited with the right options package. But don't be scared of the air suspension, I love mine...and as a city dweller it comes in handy all the time.

Three very different vehicles.

We're going to be providing separate reliability stats for the gas and diesel with the next update--members can already access a preview--because the reported repair frequency is much higher for the diesel, though better with the 2015s than the 2014s. As noted above, the air suspension can also be problematic.

Overall I'd expect the JGC to be the least reliable of the three, and the QX50 the most reliable. It's just about the only thing against the JGC, as it's an excellent all-around vehicle otherwise. The 2016s could be better, but we have very little data on them so far.