I'm actually considering setting up a .5-1.5 bbl pilot system. Economically, I can't justify doing that instead of just putting the money into the full-size system, but it would be fun to have around for pilot batches and one-off beers down the road.
Realistically, I think my 10 gal home system will be our "pilot system".
I'm gonna brew on my 10gl TopTier system. For us, it's still gonna be a hobby, but one that makes a little money, or at least helps pay for itself. We've now got two committments for taps at local places, and that's all we really need. I've done the math on this and even with the serving places doubling their money, I can still make enough to pay for this to pay for itself.
We have no delusions of quitting our day jobs. And have got our sytems down where we can brew 2, 10 gallon batches in less than 8 hours. And if things work out, we have a line on 3, 30 gallon used boilermakers for under $500.