The thing with automatic lockers, whether it's a Detroit, LockRight, Spartan or whatever, is that they never let either tire turn slower than the ring gear, but they always allow one tire to turn faster (to "overrun"). That means that when one tire loses traction and starts to spin it will drive the other tire at the same speed. This is good because it gives really positive traction.
However when you have traction and go around a corner the tires have to turn different speeds, with the outside tire going faster than the inside tire. In that situation an automatic locker allows the outside tire to overrun and only drives the inside tire (yes, contrary to popular rhetoric, an automatic locker is the only differential that actually gives you one wheel drive). That is where the handling quirks come from.
In the rear they are pretty noticeable, but generally very manageable. you'll get some minor torque steer as you push off only one side of the vehicle. Also it can be easy to spin the one driven tire if it doesn't have enough traction to drive the vehicle forward. This, at best, results in annoying tire squeal wheel starting around corners (why I don't recommend an automatic locker for heavy towing). At worst it can cause a spinout if you're on it hard enough that the outer tire breaks loose when the locker automatically reengages, which happens pretty harshly (why I don't recommend an automatic locker for someone like my wife).
In the front at high speeds they are very dangerous as I described above. At low speed they give the same characteristics as in a rear axle, but greatly magnified because of the steering and the additional traction due to the weight of the engine.
As you go around a right turn the left (outside) tire overruns, the locker drives only the right (inside) tire and the steering wheel pulls hard to the left, trying to straighten you out. Similarly, if you are driving straight and the left front rire loses traction the locker will keep driving the right front and the vehicle will pull left pretty hard. If you're going slow in either of these situations you can catch it before it gets you in trouble, but it's annoying.
If you combine the two situations and have low traction while going around a turn you'll tend to over power the tires, often spinning both of them, resulting in the vehicle going straight ahead rather than turning at all.
Unlocking one hub means you won't overpower both front tires so you won't plow out straight ahead as badly, but you'll get a lot of torque steer any time you get on and off the throttle, as the one side being driven pushes the steering one way or the other.
If you want really positive drive in the front axle, won't use 4WD at higher speeds, and are willing to accept the vehicle not wanting to turn in mud or snow, and jerking the wheel back and forth in your hands on less slippery surfaces, then an automatic locker can work.
If you want really positive drive in the front axle, aren't willing to deal with all of that but are willing to deal with turning a locker off and on, and are willing to pay more, a selectable locker is what you want.
On the other hand, if you want none of those issues (other than cost) and are willing to settle for only much better traction rather than really positive traction, a TrueTrac might be your best bet. Personally I still wouldn't recommend one for driving on a snowy freeway (no personal experience, and I'm sure it's WAY better than a locker, but it will still have some of the same characteristics), and if you lift a front tire in the air it won't drive the other tire (unless you ride the brakes a little). But other than snowy freeways or rockcrawling it's probably the least offensive option that will still give really good traction.
