Just clarifying the LSD test thing...
The LSD is not smart...its just a friction thing that holds on until there's too much torque for it to hold on, and then, its lets go, at its "Break free" torque setting....
IE: Think of the LSD as always locked, by a lock that's not real strong...so the tires turn to gether at first (So the test works), and only differentiate if one tire has TOO MUCH torque, and then it lets it slip...
Its a Limited Slip Differential.
As for a locked hi-range...
It fine in mud, which doesn't really need low range...and hi-range primarily falls short in rocks, which is not a 2wd forte anyway....and in hill decents.
So - having only a high range means rock crawling is not a good idea, unless you have REALLY patient freinds...
A locked 2wd hi-range will get further than an un locked 2wd hi-range though...so its not a waste afterall.
A locker in mud of courrse isn't the be all and end all...as the tires tend to spin the same speed in mud anyway, and you rarely lift a tire in mud either...so a locker isn't going to make you superman.
On dirt, hill climbs, etc...the locker will shine though...and may cut your winching buddies a break now and again.
While the diff's open, you could throw in a set of lower gears, and try to compensate for the lack of low range/the larger tires you'll no doubt want to mount.

_________________________
- TJ
2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes....
Friends don't let friends drive stock.
http://www.gifsoup.com/view/501230/tj-tackling-crawlers-ridge-o.gif