SMP support maturity? AMD64x2 or FX-57?

[Brandon Fosdick]

SMP support in FreeBSD seems to be a perpetually favorite feature to gripe about, but every release seems to say that its getting better. I'm about to build a new server and am trying to determine if I should go with dual procs or just a single. The AMD64x2 is slightly cheaper than the FX-57 so I'm leaning that way, but it would be a rather pointless savings if SMP isn't well supported. 

So, is SMP in -STABLE ready for primetime? Can it really make use of two processors?