I've got a BR1600 that I thrash. I use it for recording real instruments and vocals with microphones. I use a drum kit (not electronic), no soft synths or midi and very little direct injected. Mikes on guitars and amps etc, but not played loud. In that way it works for me just fine. If I had a Tascam, Korg, Roland, Yamaha or Fostex I'd use it in the same way and it'd make very little difference to how I use it or, I suspect, what it'd sound like. I just happen to have a Boss and I've had it for years. At the time I bought it, it was probably one of the best for the price.
The room (ah, attic) I record on it in and the types of mikes I have and their placement would have the most impact on the sound I get regardless of whether it was a stand alone unit like the BR1600 or a PC recording chain or 16 bit or 24 bit or 44.1khz or whatever. I also find no need to use an outboard pre for exactly the same reason. I get the sound out of it that I'm after.
It has it's limitations especially in it's lack of visual editing and the fact that you can only use it's internal palette of effects and sound processors but rather than suck everything out of it into a computer for editing and mixing (which I can do and do have) I just use the Boss on it's own all the way to the final mastered result. You can do a lot of things on it that you can do with visual based software but it's more time consuming and you have to dip into the manual quite a bit to get the hang of it. I just find it easier to treat it like you would a tape multitracker and spend a bit more effort on recording the parts as best as I can in the first place. Then again, I'm not after quantized, pitch corrected girly perfection. I want it to move around. If I was more into beats, midi, drum loops, soft synths and heavily processed vocals then I would go the PC path but I'm too old for that shit.
$600-$800 sounds about right for the BR1600 at the moment. All in one for six to eight hundred bucks or greater flexibility and editing ease of use for whatever it costs you to set yourself up using a PC based chain? Depends on where you see yourself going with it and what your real budget is I guess.
I'm staying right where I am but if I was buying new today with what I know now then I'd probably go laptop, four to eight channel mike pre/interface and Reaper and run it at 24/48 or 24/44.1. I maybe could just do it now for eight hundred schimoolies but I could definitely do it to the level I'd want to for what I paid for the BR1600 five years ago.
But it'd all have to be quiet and that's one of the great things about the BR1600 - you can have it right next to you and record soft guitar parts using a small diaphragm omni condenser and you won't hear it - no fan and almost no disk access noise. There's more rustling, farting and breathing coming out of me at rest than that thing in action.
G