I can agree and dissagree with things Tafkans said.
Overall I would say the PC version of '07 is better than the 360 version as it gets regular support (the bug/patch issue wasn't a great example of support either), has a much better interface and a much larger db.
The 360 version has speed on its side though, it processess days/games at a faster rate than any decent PC can, which is an impressive feat for a console.
The 360 version of FM '06 is great however, only a minor save bug nuiscance that can be avoided if you know how, and it's a virtually fault and bug-proof port of a PC classic.
Better speed and a 'legend' interface (the 'tab' UI of 360 '07 was one of the main irritations for me) that hasn't been beaten in console management games before or since
IMO mean it still gets played by myself alot to this day. If you can tolerate the out-dated squads, I'd recommend picking '06 up on the cheap to see how great it was done originally.
So yup, for modding, patching, the future and interface, the PC version of '07 should be the one to get.