All right, overtime at work so time for a new DAP that's worthwhile

I'd go for the Cowon J3 (8GB $175 new Amazon) or Cowon C2 (16GB $155 new Amazon).  The C2 is the new model which is succeeding the D2, but the reviews are a bit mixed:

http://anythingbutipod.com/2010/11/cowon-j3-review/

http://anythingbutipod.com/2011/07/cowon-c2-review/

http://anythingbutipod.com/2010/12/top-5-mp3-players-of-2010/

If you're familiar with Cowon players, there are no surprises with either of these.  Unfortunately iRiver and Sandisk (Sansa) haven't released anything that interesting lately, so Cowon's the only game in town.  The J3 and C2 have great playback out of the box and don't need to be Rockboxed.  If you use microSD, you can opt for a lower internal capacity (J3 8GB) to save $20-30.  Amazon seems to have the lowest price, but I'm sure you could shave another 10-20% off if you hunted around for a bargain.

The DAP community seems to like the J3 the most, but if you need to save that extra $20-30, you could do just as well with the newer, less functional C2.

How about a hifiman? The 801 is great if you dont mind parting with the moolah, if not the 601 is still pretty good.

I have no personal experience with Hifiman DAPs, but their products have gotten savaged on the anythingbutipod forums.  The ABI guys know what they're talking about, and the Hifiman employee who came to defend the HM-801 didn't give a very credible response.

http://www.anythingbutipod.com/forum/showthread.php?t=54879

I have a D2 and it's not my favorite player (due to issues with the filesystem and bad ID3 tags), but the SQ and battery life are awesome, and if I was upgrading, I'd probably go with either the C2 or J3.  I've dropped my D2 on almost every surface imaginable and it has permanent residence in my bookbag, and the screen still works perfectly.  The first thing I did with the D2, though, is to put on a screen protector and buy one of those Asian plastic soft cases, which has probably helped its survivability immensely.  I'd highly recommend investing in a protective case and screen cover for any DAP, as my D2 has been through quite a lot, and has traveled to almost every continent in the world :)  I purchased my D2 right when it came out and it still works perfectly, and the battery still holds an impressive charge.  I'd estimate, fully charged, it gives 20-30 hours easy, but I also have the screen turned down and avoid as much backlighting as possible (display configured to the shortest possible backlight time before the screen goes dark).

Good luck with the purchase.  Sounds like you've got a good handle on DAPs, since you buy Cowon and Sansa.

Edit: Another thread here reminded me of the Cowon S9.  Another great Cowon player, and cheaper than the J3, but it is from the D2 era (2008).  It's pretty similar to the J3, but the J3 has the edge in both performance and features.

http://anythingbutipod.com/2008/12/cowon-iaudio-s9-review/

^^ I agree with you. Hifiman may not be what you want if you prefer neutrality as the guys at ABI talk about. However, they have a nice warm lushness to the sound and are packed with detail (especially the 801s). They do have some treble roll-off but imo that is compensated by the thick lush mids and sweet overall intergration of the sound. If neutrality is your priority the sandisk sansa clip+ is a fabulous choice.