It can be portable it just doesn't need to be. I was something with very good A/D and that records to a common removable media, to put in my home 2-ch system. (My computer is in a different room than my A/V.)
Something like the Ikey RM3 feature set but that won't suck; or the Tascam SSRxxx that does 24/96 at a more reasonable price.
I currently have an R-4, and maybe I should just use that?