Reinier, I had both the MVH-400AH and Sirui VA-5 for a while. The Sirui does weigh a little more but is very close in terms of size and compactness.And what about the MVH-400AH? Cheaper and lichter. I am thinking to buy this one for my swaro ATC 56.
The absolute advantage the Sirui has over the Manfrotto is its functionality. It really works much better and is definitely more solidly built. I used the small Manfrotto in combination with my Opticron mm3 50 ED but, eventhough that being a small and light scope, the Manfrotto was strugling to hold the Opticron. Not to mention that I never really felt like it was gonna stand the test of time. The Sirui on the other hand is a real joy to use. I sold all my fluid heads and I swear with those Sirui heads. I am considering an ATC as well and I already know I'm going to buy a second VA-5 when I purchase the Swaro.