Mike, there truly is no joy like walking a golf course completely unencumbered with a caddie carrying the bag. There's no joy for me in shelling out caddie fees (unless it's an Evans Scholar, in which case there's some real joy), but if I could make one robocaddie purchase, the feeling of walking off the first tee box with absolutely nothing on my shoulders except the dread of my impending lost ball search is an investment that might just be worthwhile.
John, the S7 looks like a contender. Expensive as hell, but it's hard to put a price on the benefits of a mute caddie.