I like the KISS principle myself(keep it simple,scot..lol) a blowgun is about the ultimate.A singlestroke pneumatic would be next.There are always compromises. MPP's can be almost bulletproof,springers as well,IF the quality is there to start with AND the system is not being pushed too hard.A full size springer will last for decades without trouble,(spring as well) at 10 ft/lbs.push it to 18 and you'll be working on it yearly(or monthly).A benji used mostly at 8 ft/lbs, sometimes 12,will last decades as well.but make it do 16-18 all the time and expect to go thru parts.Many of the 40 year old co2 guns(bulk) I see work fine with nothing more than a few drops of ATF in the tube.
I guess I'm saying that airguns are inherrently complex,(compared to a singleshot rimfire,for instance).It's all relative,even a PCP system is very simple compared to a cd player,scooter,or, full suspension downhill bike.You can reduce the likelyhood of problems by purchasing well made,lower performance designs (very much like the choice between a singlespeed hardtail and a 21 speed full suspension bike)
I think you'd like an old crosman bulk gun(114),but your temps wont let it work for much of the year.