To answer the OP's question: I think Dish still uses 1440, but please, the resolution is NOT as important as the bit rate and the aesthetic choice is of clarity showing flaws in PQ--as is often reported by DTV users vs. a bit of softening to keep those pixels from showing their ugly presence--as is reported by most Dish users.
First the 1440 resolution is one of several official HD resolutions. Also, I can tell you from experience of that I have seen content on video disc in 1080 X 1920 that looked WORSE than Standard Def 625 or 576 content on video disc that was easily superior because the bit rate for the SD was at least TWICE that of the HD and it was transferred better than the HD content. The SD looked more like HD than the lower bit rate HD. Now, when it comes to television transmission, a 1080 X 1440 with a good bit rate is going to be superior to a 1080 X 1920 with a lower bit rate ANY DAY. Bottom line is that the 1440 Dish resolution has never been and still not the problem with Dish's PQ.
I can tell you that until recently, Dish PQ was EXTREMELY good (I had compared my OTA local and the Dish sat local using the Dish PIP feature to compare the two and I could detect only the most SLIGHT difference on a mole considering there will ALWAYS be some loss when transcoding for the fiber feed, then re-encoding for the uplink in the mux, it was impressive how good the PQ was) and for almost every one who said one DBS service has better PQ than the other, an equal number came to the opposite conclusion.
However, recent times has seen the PQ on Dish diminish. I am being honest, but the current PQ is far from being a deal breaker and has not diminished my enjoyment of the content , and it is extremely rare that I would notice it, and it depends upon the channel. Dish does provide better PQ for Premium, most watched, sports, and grown-ups content channels while the kiddie channels seem to look just a bit inferior (something the kids would never notice) along with just a slight inferior PQ with some of the most stupid, useless entertainment channels nobody watches (including those shopping channels) that Dish must carry in order to get the channels people want, so, yes, the PQ depends upon the channel. In fact, I'm still impressed Dish has been able to maintain the PQ quite well with all the pressures of the changing TV landscape.
I've found that everyone will have to reset the settings on their TV when they switch from one DBS provider to the other and to cable, and I even have separate settings for my streaming services because NONE of them send out the same values on the PQ. So, first use a Blu-ray calibrator to get your TV at its ideal best. Then the first time viewing Dish, you will need to slightly to adjust (as I have to do for all my sources) to compensate for that particular source, in this case the output of the Dish DVR or Client.
Then you will find that if you view your TV from the average distance, it is still good PQ and not anything distracting. That is not to say that on rare occasions if I happen to walk 2 ft. by the big TV I won't see occasional flaws, especially the black level, but I don't care because I don't see those flaws from a few feet farther away at my viewing seat. Also, it seems to me that Dish is maintaining the Color on HD very well.
Add this to the clear superiority of the Hopper 3 and its 16 sat tuners, option of 2 OTA tuners, PTAT, PIP, 4 channel PIP, and Dish's leading in tech, such as the coming Hopper+ that will best integrate viewing options on Apps via the internet, I don't think you will be bothered if the PQ is a bit different because almost no one who has made the switch has, either. It really isn't an issue except for those of us who do have picky eyes and high standards, and if I am choosing to stay with Dish with all its warts (and DTV has its warts, too) it says a lot that I have not cancelled my subscription because I do still find the experience overall superior.
And BTW, Netflix and Hulu and even Amazon can show some pretty awful black levels and they are persistent in showing a MOUNTAIN of film grain and distracting artifacts on content that was not transferred really well, like older TV shows shot on film transferred in a hurry to HD. Some softening by the streamer would fix that up quite well without losing the resolution or superior color of HD. Anything raw in the realm of video and audio is NOT necessarily a good thing, and, in fact it is usually bad. There is all kinds of tweaking and enhancements and processing in the art of film and video transferring and even in audio properly applied compression is NECESSARY even in high dynamic range audio like CD or DSD. There is some music that would NOT be listenable if we used the entire dynamic range of digital audio. So, tweak away until you find what you like.
I don't think you will find the PQ objectionable. I am well aware of the DTV quirks that irritate its customers, and I think you will find the Dish quirks that irritate its customers the only thing that you will make you aware you've switched from DTV annoyances to Dish annoyances, and that's it. No matter where you go, there are always problems, right? The PQ on Dish won't be the issue.
Let us know how your change to Dish works out.