I'm pretty happy with the Manfrotto 502AH, but I guess it also depends how much weight you need to put on the head. Otherwise a high hat with a proper ball head?
I have the new Manfrotto MVH500AH which is the replacement for the 701. It has many improved features over other fluid heads: it uses the new top-loading Manfrotto quick release plates (far superior to the rear-loading plates IMHO) and it uses real fluid cartridges for dampening--very very smooth. Compared to the 501/2/3 heads, it's much smaller and compact, whilst still having a robust build quality and good load capacity.