I don't have motorized jacks on my hawk, they're the hydraulic jacks that were more prevalent prior to the screw jacks becoming common that we tend to see now. I did notice an improvement with the jacks off, saves over 100lb in weight but also wind resistance, seemed to pick up 1+mpg with them off (which is good when you're in the 12-13mpg range).
Yes and no on the repair part, depending on who you're talking about. Sure the average Joe can caulk up a cut in aluminum siding but you can make similar non-aesthetic repairs on composite stuff. To really repair damaged aluminum siding means replacement which is a bit more involved than just a hardware store run but might be more familiar for someone used to working with fasteners, etc. On the camper I'm building, I've built it so give me a random orbital sander, some resin, and fiberglass cloth and I'll be able to make a repair if I have a puncture/tear in my siding. Trickiest part would be blending in the paint work but I'll likely be using something more like automotive paint, not a jelcoat (my home built camper is all hand laid over a foam core, no molds and thus no jelcoat). That said the likely hood of skin damage on a foam core camper verse a FWC for instance is going to be quite a bit lower, I've posted pictures of what hitting some samples with a hammer will do on various layups, while various degrees of damage occur I have full confidence each one of those hammer blows would have punctured the siding on my FWC.
All that said I'm not against aluminum framed campers at all, I just decided to pursue the composite route for my build. In your other thread I even said I'd probably consider a hybrid route if I was to build another camper in that I'd do a aluminum frame to an extent with foam blocking glued in between and then laminate manufactured skins to both the frame/foam. Then traditionally affix the interior with screws. It would be heaver than foam core alone but I think the fabrication would be faster which is one of the things I'm finding on my build (its time consuming). If I already had an aluminum welding setup/skills I might have went that route off the bat, dunno. I just happen to recognize there are pros/cons with various construction methods and enjoy looking at options. I don't have a burning desire to unilaterally declare one "superior" and shout it from the roof tops. I don't really factor in the cost of a depreciated used aluminum camper verse the cost of new construction when talking about a "superior frame construction". It is definitely something to consider from a value perspective but doesn't have anything to do with construction to me.
My dodge 1500 4x4 quad cab short box had air bags and E-rated tires, it handled the camper pretty well with those two things but the braking could have been better in panic stop situations. I needed to make a choice to keep that truck or pursue a new one before changing the truck out to a flatbed for the camper I'm building. I desired better brakes and a larger gas tank on my 1500, for the money it would have taken to make those modifications I could swap my truck out for a similar 2500 so I opted to make that change with the benefit of getting a stronger frame/axles, etc. as well. I also went a few years newer on the truck but that really doesn't factor into the 1500/2500 decision. The 2500 did take some front end work to get it to handle a bit tighter due to the solid axle/link design where as the IFS 1500 was pretty good off the get go. I just changed trucks a couple months ago and haven't put the FWC on this new truck at all yet so no feedback on how it handles it but plenty of other folks with similar trucks like the ride. I will say with the 1500 I was right around the GVWR without any water in the camper with just me and a full tank of gas (keep in mind I have 160lb of battery in my camper as well), but that is also on a 4x4 platform. If you're talking a 4x2 reg cab truck they've got more room to play with. Also as I said before one can always make their own decisions on GVWR, I wasn't worried about breaking the truck but I wanted more braking and gas capacity which happen to come stock on a truck with a higher GVWR so it makes sense in my situation.