I'll try to keep this short. When we 1st were looking for a new truck back in '03 our DS was still in a car seat and DD wasn't. We looked/sat in both GM/Ford CC trucks and felt the Ford just had more room. Ended up going w/ a '03 F250 CC,4x4,SB 6.0. Had that truck until late '14 and upgraded to a '15 F350 CC,4x4, SB 6.7 simply based on past experience w/ Ford (despite the 6.uh-oh). Made a very good decision as this was a great truck even if off the lot purchase. HOWEVER, when we decided to upgrade the RV a couple years later, we were over truck's everything. Sadly, as much as I didn't want to do it, we traded in the '15 for a '17 F350 DRW, CC, 4x4, LB, 6.7 and quite frankly am impressed w/ the room it has and slight uptick in power over the '15 but the '17 also has 4.10 gears. FWIW, our DD is now married and 2 hrs away, DS is attending college so just the DW and me. I will not give up the CC, but still sorely miss my SRW trucks.
Now as for GM VS Ford, OP, you've gotten some great answers/replies and most are very passionate about what they drive. You won't go wrong w/ the towing/pulling ability of either brand. GM has the D-Max/Allison down pat and so does Ford w/ their OWN Powerstroke/Torqueshift. You'll just simply have to look at, sit in, test drive each one to see what you like best. What I'd suggest is that the 2 of you go at same time, write down notes separate from each other (also make/model/trim level of each truck), take turns driving, etc, etc. Once you've done all this, sit down at home, make a spread sheet and compare what you liked/disliked. Then from here you'll reach a decision. I along w/ probly many others don't agree w/ the prices they are asking for new rides, but not much we can do about that. While things seem to be pretty quiet for pick-ups, the DEF systems are an absolute nightmare on semis. When they work, all is great. When they go down, biggest pieces of junk no matter what brand. In saying that, once a pick-up goes out of warranty, can be pretty pricey to get fixed. So it's either keep trading in every few years to have a warranty or "suck it up buttercup".
Each truck, just like anything, has their own set of quirks. While my all time fav truck is a GMC, I simply have had decent luck with Ford and the Ford IMO just looks like "muscle" truck.
Sorry for not keeping this short.