Yeah, I`d advise a reel to reel if you can afford it.
I`d love one myself when I have more room.
But it has to be something good, not some shitty fostex 8 track or something.
It`s great for mastering, the saturation it adds is lovely (ie: distortion), although there are some nice saturation plugins around now.

But again, different machines add different colouration, so you really need to research what you want, and how you can get it.

Same with compression really, just running something through valves that add "colour" is no good unless you know what colouration you are looking for and how to get it and use it effectively.