The pros of non-PC hardware DAW - no need for optimisation and hassle. Just plug-in and use it. Stable (you don't get BSOD like Windows). You get nice faders (many comes motorised) etc. Many of them still let you plug in monitors so you can still use large screen to work with. You should also (theoretically) get more tracks mixed in one instance.
Cons of hardware DAW - price, less verstatile.
Pros of PC DAW - main thing is the low price. And everything that gksingapore mentioned above.
Cons - it's hard to work with just a mouse in mixing. You'll still need to get hardware midi controllers that let you use faders and knobs. You'll need to optimise it - so may be more time-consuming (at least in the beginning stages). There's the danger of the dreaded BSOD if you're using Windows - but with careful tweaking, that should be minimised. But one BSOD in the middle of a take can make you go crazy...
I may sound anti-PC DAW here, but really I'm not!!! I'm very pro PC DAW. I just want to balance the opinions. PC DAW is very versatile and expandable. It can hold more RAM, easily expandable and upgradable etc. There are still limitations to amount of plug-ins, but with software like FX Teleport, you can have a farm of PC racks connected via ethernet to give you limitless plug-ins. You can do much more with audio software than the studio workstations.
