Andy - Given the choice I'd always opt for a colour enlarger for all the reasons already posted here. The convenience of dialing the colours as Ian said will have the same effect on B&W as using filters, without the disadvantage of having loose filters that can get scratch lying around. Also I prefer the diffused light to the harsher condensed light.
After lots of advice here on APUG I eventually went like a bull at the gate for a Meopta, although I needed to do some work on it the "tractor" technology made it easy for me to strip and rebuild over a few hours. The real advantage though is I can use it for 35mm to MF negs