Here is my 2cents:
I just did exactly that. . . . weld the front end spider gears. I wish I had NOT done this!
While it certainly provides positive traction up front, it manifests a lot of gremlins that was not evident before.
Since the front drive shaft normally does not turn when driving (on the disconnect models such as mine), it now will turn all the time. This showed up a hellacious vibration up front. Caused me to replace every u-joint in the rear shaft as well as the front, and I still have the vibration. Seems now I will need to either balance the shaft or get a new one.
On the non-disconnect models, the front wheels are constantly locked and will skip and chirp on tight turns just like the rear wheels will on a welded rear axle.
I say lock both ends. Do a Detroit or Ox locker out back and a Powertrax or Detroit up front.