No one test kit brand is good for all IMO. Seems like most do somethings well and others poorly. For instance I like the Salifert MG, SR tests but their pH sucks IMO. Tropic Marin's Calcium and KH are the best you can buy but their pH and Ammonia have problems.
The SeaTest and Salifert Calcium tests are identical, use the same reagents and both are good though I think Tropic Marin's is far superior.