If you are running hubs, you can get away with a full time locker in the front a little easier. Unlocking one hub ensures you can turn and eliminates some of the driveability issues, but the vehicle will pull to that side a little due to the extra drag on only one wheel. Locking both hubs but leaving the t-case in 2wd will result in some ratcheting from the front, but no driveability issues most of the time. A posi will have issues even in 2wd. The clutches don't care if there is power to the driveline or not, they hold the same regardless.
I've had a Powr-Lok in the front of my ramcharger for several years. I like it, but it is a pain on ice and slick surfaces with the hubs locked in. It also takes a lot of effort to steer with the hubs locked. If I engage 4wd, it almost makes it drive better, since the front tires are pulling, not just being pushed. I had a Lock-Rite in the front of a single cab F250 for years. Aside from times when there was power going to the front tires, it was barely noticeable until you put power to the rig and it started pulling with the front tires. Putting it in 2wd eliminated most of the issues, on everything except super slick ice. Part of my success was having a diesel, with a big bumper on it and running 255/85/16 front tires. They had a lot of ground pressure, so they would force the locker to ratchet, rather than slip on most surfaces. A lighter rig, with bigger tires may not have as good of luck.
I like ARB's I have one in my other rig, but haven't used it yet. The only problem with a selectable, is that you have to remember to turn it on, and you have to disengage it when you want to start turning sharp, or you will have issues. I don't agree with the name of a selectable locker, I prefer to call them selectable spools, because when you lock them in, there is no differentiation in the wheels at all. A locker ratchets and lets the outside wheel go faster, thus allowing steering if the surface doesn't require wheelspin on the inner wheel.