i have done some hard core wheelin in my old 1ton.
had 38" swapmper tsl brand new with detroit rear open front.
i will say this. yes locked is great
BUT when in snow/loose stuff like sand n gravel or on road drivin in crap you first and formost want open diffs. i would rather spin a tire first than have my rig slide sideways as thay tend to go when there locked and you apply power and thay try and move.
when i had more than 1-2" of snow on the ground i HAD to lock in the 4wd to get anywere. as the rear locker made the truck just wana spin around in a circle. everytime i hit the gas it went right . i let off the gas right back to stright.
when i had the gov-loc in there before same everything on the truck that thing was a whole diffrent animal in the snow. nice and easy went just fine. need traction tap the throttle for little wheel spin and click she would lock in just fine and away i go. then when done she went back to open.
and just as soon as i swaped in the detroit it went to no fun to drive on the street unless in 4wd if in the snow.
the best all around info i have read on this over the years from others and stuff like i just typed here is this
i now have my current project truck STUBBY
http://coloradok5.com/forums/showthread.php?t=245582 ya its on hold for now for many reasons. BUT i picked full selectable front and rear. i went arb's as most everyone liked them in the 60's and 14ff's . now i have open/open or open/locked or locked/locked or locked/open tons of options. to me this is the best way to go in my mind for what i want to do with my rig.
now most of my plans for STUBBY are 98% like what you want to use your rig for. and since i went arb's and i know i will be drivin it hard off road and being full locked at times . plus 38-40 tires and lots of stress on the driveline from things like 3 stick doubbler for front digg's then i went spicer hubs with the inner gear broched out to 35 spline. then yukon shafts with nittro joints. ya i also got dedenbear/reid racing knuckles so i could get a beefy steering setup. then i can also use the 5th stud hole on the ord crossover and high steer setup that will have hydro assist on it. you dont need to get this crazy tho. i had the cash and said screw it now or never.
bla bla bla i could go on and on. but i hope you get my points i made. if this thing will see any street time and you want true safe reliable handling in snow/heavy rain/and other crap i would go selectable in the front for a minimum.
and dont forget. you said you pickup people and take them to the hospital or fire/ems places if the weather is bad. do you realy wana be drivin in your rig and hit somthin and be locked all 4 and have the rig suddenly go sideways like its on glass from loss of tire grip to the road and then all 4 lose it cause its locked. ? i have had that happen it will pucker your sphincter right up fast as you can blink a eye.