I switched from sump systems to a sealed pressure system a long time ago. The main attraction, for some, to the sumps is the larger available area for bio media thus supporting a greater biomass. (read...overstocked)
Other conciderations are ease of maintaince, reliability, and safety. Differant filter systems excel at differant things. The concept of the 'Best' system could no doubt be argued for weeks without a solution. In my opinion the 'Best' system is the one that fits your needs with the least headache.