I have used the red sea pro titration test and now have a hanna. The Hanna for calcium is a little more involved than their other checkers, but it's still easier than a titration. Plus it uses a micropipetter which makes me feel very sciency every time I use it (Ahhhhhhhh..... organic chem.....).
Accuracy-wise I've found it to be very similar to the titration kit. Can't speak for the salifert, but looooove all my hanna checkers. Wish they'd come out with a magnesium checker (the only titration I still have to do).