I used a locked (welded) diff one time as a budget racing solution and I had no problem under power but lifting off suddenly in turns (if you had to in an emergency) the stability became unpredictable at best and unsettled the chassis in a major way. That was my one experience of it and I never repeated it or wanted to either.....
A Detroit Locker gave a similar experience and took some getting used to!
Give me an LSD any day...
