I have used Roland recorders and they are nice, although it's still only 8 simult. recording on that unit itself. You need another device to get 16, and then when you get the expansion board. The quality still drops alittle bit. Only 8-tracks can be recorded at 98kHz. The Korg D16XD is the same with 8 channels on board, 16 when you get the expansion board. Both products are great, basically what you pay for is what you get with them.

Rolands biggest plus and probably why you pay so much for them is because they come with "everything" you need to make a professional CD (they all say that, but Roland studios actually do it). A ton of extras that most portastudios have but not quite the extend and quailty. Such as 'modeling', and mastering tools that are simply amazing. Mastering tools are a very nice bonus, and do come in handy. The modeling however was something that you only need if you dont have the an amp, or a nice microphone.

Between the Korg and Roland, Korg to me was alittle easier to learn and begin using to it's full potential. On the Korg everything is basically there and ready to go, where as the Roland. You be doing some tweaking and engineering of the sound. Thus it may take you alittle while longer to get used to a Roland.

As for recording sound quality, they're about the same but with slightly different characteristics. May just be me but KORG sounds alittle smoother, Roland has a more modern sound to them. Definitely see if you can check them out personally. My friend actually thought the KORG recorded sound better than the Roland, I didn't.

The Computer end is definitely a good path to go down. There easier to expand on. However the better computer audio interfaces require that you have a reasonable powerful PC or Mac at your disposal. If you want to go that path, make sure to take a look at the requirements needed. Mac's are tailored made for such purposes, on a PC you'll want at least 2.0 GHz processor or better and a Gig or more of memory.

Hard Disk recorders are nice because it will record 24 simultaneous tracks. Then you can export them into any computer with a nice audio card (technique may very; USB, S/DIF, or Audio out to Audio in), and do all the mixing and editing on there. Basically your paying for the recorder and thats it. The only downfall with HDR's is the quality you need for a professional sounding recording is gonna cost alot of money. The 16-bit, 48kHz ones are actually pretty cheap but still sound great especially with a nice Audio card. The one I used was a Mackie.

In terms of all around purpose going the computer end is the way to go.

I hope that helps.