crab is correct. Disc loading has a significant impact on establishing at what ROD the rotor system enters VRS. It takes a lesser ROD with an empty helicopter at the end of the fuel cycle vs. a helicopter at max gross weight.
To make a slight correction to VF's contention that the Vulchard method doesn't work in fully developed VRS: in a tandem rotor helicopter it is the smartest method, no matter on your ROD. Also, an S-64 Aircrane responds very quickly to a lateral control input to exit VRS vs. a longitudinal recovery. I've seen RODs larger than 5,000'/min and the Vulchard method works like a charm. Loggers have been doing this since the '70s.