I don't think you can go wrong either way.
I have a couple of the FN-produced Model 70s (a .257 Roberts Featherweight and a .338 Win Mag Extreme Weather). Both are nice rifles and are plenty accurate.
My dad has a Weatherby Vanguard S2 in .243. It is also accurate, and well-made.
As others have said, they are two of the better actions out there today. If I find myself in the market for a new bolt action rifle anytime soon, it will probably end up being a M70 or Vanguard.
In particular, I think the Vanguard is about the best $500 rifle you can buy. And I think it is well worth the extra $150-200 it costs to step up to a Vanguard from something like a Ruger American or a Savage Axis. They are worlds apart in quality. But sometimes I just want a Model 70.
SR