compiler selection

Hello, We have recently purchased a NONMEM license and we are involved in the installation. But one doubt has come up. Which fortran compiler version is the best option? I know that depending on the version, the results of a modelling exercise could change and also the processing time. I will install NONMEM in a HP Pentium 4 computer, with Windows XP I have reviewed recent literature, and for most of the cases Digital Visual Fortran is used. I would add that only 10% of the manuscripts include information about the compiler. And maybe a silly question. Is there any difference between Compaq Visual Fortran and Digital Visual Fortran? Let me know your experience, and the reasons to base your selection. Thank you in advance, Mark