The Belgian airforce have been plugging away at how the F-35 will be more cost effective than maintaining the F-16, but there has been a bit of a scandal over the figures for the maintaining the F-16 as they were found to have been padded out a bit to make the F-35 look a bit better.
Still no "official" government comment on whether Belgium is going to take the F-35, the Euro Fighter, or keep the F-16, but the airforce seem to be pushing the F-35 for all it's worth