Very important caveat: I come from the audio world. I have a nice display which has been professionally calibrated, but I am otherwise not an experienced judge of video equipment or picture quality. The contents of this post is my uneducated, wet-behind-the-ears opinion and also includes my wife's commentary. No insult or injury is intended! That said...
I had an opportunity to evaluate the 78, 79, and 27A side-by-side earlier this week. (My local dealer let me take all three home at the same time.) A caveat on the 79: I unfortunately did not have access to an HDMI cable, so I only looked at component-driven progressive output. I evaluated with a Sony XBR CRT display and AVR300.
Here's what my wife (better eyes) and I (better ears) saw/heard...
- 78/79: Compared against our current Sony midlevel DVD player/recorder, both of these units had fantastic audio. I wasn't really expecting this because the players were both connected via digital coax at the time, but the improvement was, in a word, dramatic. (I guess this means we're hearing differences in the transport mechanisms?) I'll leave the audio superlatives to others: suffice it to say that both players sounded like Arcams. The video between the two was fairly close to identical, though we found that we slightly preferred the 78 over the 79 -- a surprise, given the price difference and official test scores. We also found that in both cases, when we began switching back and forth to/from the Sony with the same material and with DVE test patterns, we preferred (!) the *Sony* image: it was sharper, had better coloring and depth, and was slightly less green. Single-blind and with the sound off, my wife was always able to tell the difference and always preferred the Sony. She said the Arcams looked paler, grainier, and seemed washed-out. Ultimately, even though I was hoping to settle on one of these players (less money, same exterior design as the AVR300), I wasn't able to justify the price/performance ratio on the video side.
- 27A: We found this unit to be superior in every way to the 78/79 and to the Sony. There's really not much to say when something is essentially perfect! We were unable to spot any of the usual image flaws using DVE, and the same material that had previously looked better on the Sony was suddenly in another league -- nearly indistinguishable from network HD programming for depth, clarity, and color. Audio on the 78/79 was already well past "good enough" for film, and the 27A was somewhere a ways past that. We decided to keep this player and have really been enjoying it!
Others may certainly disagree and perhaps the addition of HDMI might change the equation, but in summary I'd say that if you can find a 27A still for sale, you should seriously consider it.