Like onlychild said, the Best Buy coupon would work for MP3 players. I too purchased an A728 to hold me over until the A729 is released, and can confirm that the coupon works. If they tell you that they don't take it, just ask them to scan the coupon, the 10% discount will show up.
Now I'm considering the A829 instead. If it's only $20 more than the A729, I don't see the reason not to get the A829. You never know when you'll find bluetooth handy. Now I wonder if I can stream the music to my PS3 and play the music through the speakers connected to the PS3... Can't wait for Best Buy to receive them.
As for the A728, I'm not an audiophile, so I can't really tell if it's better than other players out there, such as the P2 or the Cowon, as my last mp3 player was a 4GB Ipod mini. But it certainly sounds great to me and I'm very satisfied with the sound quality. The screen is beautiful, and fairly scratch-resistant. Although the first one I bought had a scratch in the lower part of the screen, so I had to exchange it. Video looks good, and I can read the subtitles in the anime I put in there without difficulty. Interface is very intuitive, but I must say that no OTG playlist is a bit of a let-down. I wish they put a radio in there also, but it's not biggie, as I use my Sony Ericsson phone for that. Now the packaging... It feels cheap!! I don't understand why they package the player the way they did, maybe I'll upload a couple pictures after I get home as I can't explain it very well. And on the screen of the player, there's a sticker that advertises the Best Buy Music store.... and also on the "box". I first thought maybe this is special packaging for Best Buy, but then I saw the Best Buy Music Store as a software installation option and also part of the manual.. Did they have the same thing for the A810 series also?
Anyway, hopefully Best Buy gets the A829 in soon, because it should become available today, well at least on sonystyle.com