Well, I got the unit today and so far it is average for a box, with things I like and things I don't like. For the OTA part, I think it is a good ATSC only tuner.
The only thing that I don't really like about it is that the autoscan has to find the channel for the unit to tune to that channel. Once it finds channels, you can then add or remove the channels from the channel list. There is a neat button, "List", that will bring up a list off all avaliable channels and you can just select the one you want. You are able to tune to a channel or a specific sub-channel.
The EPG only brings up the current channel with no guide screen for all channels. The remote seems to be the exact remote that is used with the Hisense tuner, except for different colors, etc. Channel changing speed seems to be quite quick.
For the QAM part, I am not so impressed. The first time scanning through my channels, it picked up over 320 channels. Most of those are encrypted, are my music choice or other audio only channels, and are the neighbors OnDemand movies. On this first scan, it did not pick up the 3 clear QAM channels I do get. So I think ok, maybe something is wrong so I reconnect my 4200a and it is working fine. So i rescan with the PHD box and it finds the channels this time. One quirk with the QAM side is that you cannot tune to a specific sub channel, only a main channel. This means that to listen to sub-channel 28 of my music choice channel, I have to punch in 63 (my music choice channel), then channel down 28 times to get to that channel. What a pain. This box will automatically add all the encrypted channels to the lineup, so I manually have to go back in and delete them. The 4200a would automatically not show those channels in the lineup. Another thing I don't like about the QAM tuner is that it takes forever to do a channel scan, and it doesn't save a channel list for QAM and ATSC. So for me, when I switch between cable and air, it takes forever, whereas the 4200a just switches the channel listings it is using.
All of that may seem harsh, but since it has usb, most of those problems are in the software which should be upgradable via the usb.
I mainly got it as an ATSC box for an LCD I'm planning on buying, and needed an ATSC box with DVI. I'm quite happy with the ATSC part of the box, with the one minor problem of having to have the channel in the lineup prior to being able to tune to that channel.
I'll post more thoughts as I use the box.