I've been moving my low gradient factors higher and higher, and totally moved away from VPM based on personal recommendations from some decompression scientist friends of mine.
Out of curiosity, what GFs do you currently run?
And I would agree with moving away from VPM. It has been proven inadequate time and time again.
Either way nobody in their right mind is doing pure haldanian deco these days. If they are, they are doing it in a habitat.