Well, I've had mine hooked up for a couple of days now. A couple of observations- in comparison to the Newpoint Theatre Director- The APC is more compact and several pounds heavier, it feels more solid and well built. The Newpoint is just a much more basic power conditioner and does not have a fancy display, but it does had LED's that indicate the voltage if it drops below 120, 115, etc, and has the Ground LED for the home's wiring, and a surge LED indicating it's active. I believe the Newpoint will supress surges, and does nothing for under voltage.
The APC has the same functions plus an LCD display that displays the voltage in and out, amps being drawn on a 15 amp line, watts being used and as a percentage based on 1440 watts I believe. You can dim or turn off the LEDs on the APC as well. It does voltage correction both ways- ie it will provide a boost once the voltage drops below the level indicated. There are 3 settings for that- as mentioned elsewhere. I've mostly noticed it when turning devices on, the H15 makes an audible click when it boosts voltage. Things aren't constantly being turned off and on for me, so that doesn't bother me.
Right now I have a wireless adapter plugged into it, dlp tv, receiver, xbox 360 and the MWF 15. I just checked out the mammoth stampede in 10,000 BC since my wife wasn't home. I was hitting 110 db during spots (receiver didn't have much more headroom, highest I've ever had it), and I did notice the Line Boost on the H15 lit up to correct under voltage. As soon as I turned it back down to a more normal level the light went off. Of course I could not hear any clicking over the movie.
So far I am pretty happy with it. I think the extra $80 over the Newpoint one is well spent. As I mentioned I had a loose screw and other pieces inside the case that I removed, but it appears to be working normally with no problems. The silver also matches the HK receivers pretty well too.
The only thing I kind of miss, is that there isn't an always on outlet or two on the H15. I know they do not recommended turning it off and on all the time, but the MWF 15 drains about 20 watts even while off, so I was hoping I could plug the wireless adapter into the always on plug, and turn everything else on and off as I come and go (the pc in the room is further away from the wireless router, so I have the adapter closer to the door and on a long cat 5 cable). Instead I think I will use the Newpoint on a switched outlet and plug the sub into that. Otherwise I would love to have everything on the H15 just so I can see how much power everything is pulling. Not that I could say why it would matter, it's just cool.