This release has some additional stuff in it besides the 0x108 release...at least that's what I think Earl said.
If you're into OTA-HD, I'd do it....otherwise you might not get a great benefit. It's all a matter of how "anxious" you are. For me, it was absolutely necessary, as OTA is the single most used aspect of the HR20 for me (recording HD OTA, that is).
I just upgraded Wednesday night to 0x108...I'm going to download whatever is available tonight (if it's announced) as well. Again, if you are interested in OTA-HD recording, then I'd upgrade tonight. I'm not one to sit around...especially as slowly as they roll out the national releases. If you are a patient person, with no OTA needs, then by all means, play it conservative. It might be only a week or two or three or four, before the national release comes out.
Keep in mind, you are taking a risk. They (D*) have said if you do this special upgrade, don't call them about it...they are not supporting it yet, and the CSRs don't know anything about it. They don't want to be questioned about a release that they specifically denied they would support. If you want/need help with this release, you are going to have to get it from this forum...period.
So...you pays yer money and takes yer chances.
My box has been VERY good for the entire 3 months I've had it. I'm not afraid of an upgrade breaking it. Who knows, with the massive amount of feedback they got in just the first few hours, they may have made OTA even better...although it is working just dandy for me. Damn the torpedos, full speed ahead!