Pros: Size, Build Quality, Sound,
Cons: Capacity, No Gapless, FLAC
I've owned 4 of these players now, not to say four have broken but I went through a bit of an ebay buying spree and ended up with several at once. Compared to newer players they are left wanting in many ways, sound quality isn't as good as my a846, for example. Battery life isn't as good as some players, especially when they are more than a year old. The 8gb capacity of the largest isn't much by today's standards, considering this was Sony's premium player at launch. Also there's no large, touchscreen, no apps, no phone, etc..
However, this was meant as an mp3 player and it does that rather well. Like all Sony's it produces a warm sound which, paired with the wrong earphones, can sound rather heavy on the bass. It is a tiny player which fits in any pocket, has a good/simple user interface and the entire case is metal rather than the plastic of a lot of cases of other players. Some complain of the hold button positioning but I can't think of a more logical place for it, it falls to the touch very naturally.
Value very much depends on when/where you bought/buy it. My first one cost me a lot of money (I forget quite how much, it can't have been that bad) and the last one I bought was under £30 from ebay. ebay is one of the few places to find these nowadays, usually, lightly used or reconditioned. make sure though to bid on a a810 series not the a800 series, they look the same but the latter are a pain to use with the sony software that must be used in conjunction, the a810 series allows direct drag & drop and you can throw the cd in the bin.
A few things annoy me about the useability of this player which are worth mentioning. There's no flac support, gapless albums will have a 2 second gap put in between the songs and you can't delete any songs directly off the player. All minor points but when combined with a relatively small capacity it means mine has been relegated to a gym mp3 player now. Being so tough it's ideally suited, i've dropped mine countless times now.
Depending what you want in a player, don't dismiss this one too soon, it sounds/works better than a sansa clip for less money. I would comment on the included earphones but have forgotten what they sound like, this is head-fi after all.