I dont have the 5-speed as I believe it didnt come out until '05 if I recall, but ours is a 3.73 rear on an '04 and I have no regrets. We've done some highway, a lot of backroads, and some fairly hefty offroad stuff including climbing up to 13,000 feet in CO over some knarly obstacles. No issues. And in one case, I blew a front hub out and had to negotiate the rest of the trail using 2-low rear only, and it was awesome. I dont do a lot of heavy towing which might change my opinion. We tow a small boston whaler occassionally, maybe 1800lbs, and the V10 doesnt even feel it. On the highway, she cruises at 65 at or just under 2000rpms.
Talk to SMB too. The only reason I might be inclined to go with the 4.10 is a)if I was going with larger tires, 35" or b)doing some heavy duty towing.
btw, the V10 is really under-rated in my opinion. Yes its thirsty but not dramatically different than some of the lower avg mpgs on the diesels. And its a torque monster. The 3.73 has done us well.