Hi Mike,
My answer is that a well built RAS, that's capable of being properly adjusted, and will hold its adjustments, is as safe to rip on as any circular bladed machine is. You also need an appropriate blade, stock that is safe to rip (a jointed face and edge), and above all, knowledge of how to do it safely.
Ripping on any circular bladed machine can be a dangerous operation. Stock that isn't flat, doesn't have a jointed edge to run against the fence, or has internal stresses that cause it to distort when cut is bad to cut on either an RAS or a TS. I generally rip only sheet stock and 3/4" or thinner solid wood on the RAS. For thicker wood, a bandsaw works better than any machine with a circular blade, and is a safer bet. Since I suspect you don't use many sheet goods, being a hand tool guy, I'd say to get a bandsaw instead.
At any rate, I see we're practically neighbors, so if you're interested in checking out how to safely rip on a good old 50's cast iron DeWalt, let me know. I also have a few books on the subject you're welcome to borrow.
DESIGN is EVERYTHING! Without good design, the greatest craftsmanship is wasted. Not all great museum pieces are of the best craftsmanship. It was design that made them a treasure. -- Wallace Kunkel, aka Mr. Sawdust