Our SOP is to limit the rate of climb or descent in busy TMA's to 2000fpm with 2000 feet to altitude and 1000fpm within 1000 feet of cleared level. In RVSM airspace, if VNAV is doing the right thing and the rate of climb is less than 1500 fpm then the preferred mode is VNAV as this provides all the safety margins that a VS climb does not. This is all related to avoiding unneccesary and unwanted TCAS TA's. (or indeed RA's at high rates of climb or descent). Hope this helps.
Maggot