Maybe it is because earlier models had problems? The non-Plus model became available in June of last year. I got a DTVPal Plus in February. So I don't have first hand experience with its earlier problems.
The Plus has a more sensitive tuner than the non-Plus. I've read some say it does better than the Zenith. I've not tried to compare the two side by side hooked up to the same antenna. But it does get a few more channels than the Zenith in our house.
My biggest complaint is that when you switch channels the channel information box blocks the top 20 to 30 percent of the picture for 5 seconds. So I have to constantly press the [Cancel] button right after switching channels to clear that away. (if it is a channel I care to see people's faces on). (sure faces aren't the only thing that might be blocked, but it is the most common). The Zenith just says the channel number (and call sign) in the top right corner.
Both will let you display that chan info at the push of a button too, of course.
(sorry for saying so much on something that probably is better talked about elsewhere)
That [Cancel] button is within easy reach. So it isn't a big deal to press.
The Zenith does have a nice [Signal] button that keeps the signal strength of the current channel dislayed. You can do that using the [Browse] button on the DTVPal. But what sets the Zenith apart is that it makes an audible beep that gets quicker as the signal gets stronger or slower as it gets weaker. This is great for the TV in the kitchen, because its antenna is in the closet that's adjacent to it. And you can't see the picture as you move the antenna.