Phil -- We're in our second year with a Pro 408, and our experience has been much the same as Mark B's and duster's. 2-1/2 to 3 yrs ago we were exactly where you are now, trying to figure out if the expense was worth it. Now I wish we'd pulled the trigger sooner. Once you get up to speed on the software (we also run Mozaik) and start cutting out that first job, you'll never look back.
A few things we learned: 1) Get the biggest ATC you can afford. We opted for the 5 tool, and often need more capacity; 2) If you have any plans at all to produce MDF doors, order the Dust Dock -- SS's standard dust collection can't keep up with hogging out all that material; 3) Yes, the 408 can handle 5 ft. wide sheets, but the vacuum force doesn't reach that area of the table, so it's problematic trying to cut small parts from, say, a 5x5 sheet. We got around this by switching to 4x8 prefinished Baltic Birch for our drawer boxes; 4) Odds are the machine will be shipped on the tail of an enclosed semi trailer, and you'll have to unload it LENGTHWISE. SS recommends a 5,000 lb. class warehouse forklift, but this isn't nearly enough muscle. In our case it took an 8,000 lb. telescoping lift, and even then we had to use 10 ft. fork extensions. It gets even more sporty if you have no loading dock!