Ok first of all heres a good site detailing everyhing about recording.
www.tweakheadz.com/guide
Next, I went the multi track rout becuase I wanted portabillity and that way I could have an "All in one unit" by all means you could use your computer just for recording but I wasn't going to.
It all really depends on your budget and what your recording.
ALso with computers you can eg. Add a compressor if you don't like your settings as with a MTR I don't think you can (still a newbie)