Both my brother and I use the Detroit Locker No-Spin units with 31 spline axles. I would definitely recommend them for street use. I have used mine for close to a year and a half and 11,000 miles and haven't had an issue with it yet. My brother has had his for close to 9 years without a single problem and close to 70,000 miles.
When cornering, I just take my foot off the gas and coast. In that vein, the rearend is not locked. However, if you gas it while cornering, it WILL want to lock up. After a few drives, it's easy to tell where and when you can "step on it" while cornering and if you ease into the gas it'll be alright.
Really, and I HAVE to say this; People overreact to these locker units. I've heard many people who have never used them promote other products because they've been "educated" by reading material (books, magazines) and not real life situations. That is how a lot of this negative publicity generates toward these units.
I think you'll be fine if you use one in your own car.