This is why I chose Acorn. The Acorn processor only has to juggle one ball. Look at your Windows task manager sometime...It's a little scary.
I had a commercially-built router that ran WinCNC, it was very stable and seemed easy to customize. I looked into it for my machine but Acorn ended up being about 1/4 the price.
Acorn's support forum is very good, my first issue (turned out to be Windows related, ha!) had a moderator response within one hour.