I cannot give an unbiased opinion here Caper, I have only used Fluvals, which I find work well, and therefore cannot comment on the other brands.
It is like the argument I had with a tele-research person a while back..
Researcher - 'And on a scale of one to ten, ten being good, how do you rate your telephone provider against other providers out there?'
Me - 'I have not used any other provider, so cannot give an informed answer'
Pause from researcher - 'um, but on a scale of...... I need to put a number in here'
Arrrggghhhhh.....