Summary: I purchased the Manfrotto 560B Fluid Video Monopod equipped with a 234RC Swivel/Tilt Head with Quick Release a couple of years ago. I soon found the 234RC Head to be of limited use when using larger/heavier lenses. When changing the orientation from landscape to portrait, the adjustment lever was very difficult to access and wouldn't tighten well enough to hold the lens firmly in place. I installed the 494 Mini Ball Head w/RC2 QR Plate, and it was a perfect fit.
Summary: I wanted a ball head for it's simplicity after struggling with a 3-way design and I'm really glad I did. I went for the smallest, lightest model I could find in the Manfrotto range to go with my Manfrotto 190CXPRO3 carbon tripod. It easily carries a Pentax K7 DSLR with 55-300mm lens and is very quick to adjust, even in the dark, as I found out last weekend at a fireworks display.
Pros: Compact, Easily Adjusted, Lightweight, Locks In Tight