The variance in DOS results is due to a few factors.
a) Some people use v1.08 instead of the v1.06 demo version. v1.08 returns higher results.
b) Some people are using Phils benchmark pack, which if I recall right, has made some adjustments to settings which alters results.
c) Other installed hardware, particularly USB, and to a lesser extent network, cards may reduce the benchmark results.
Before Phils pack, most people would benchmark using v1.06 demo at 320x200 with sound disabled. After Phils pack, there has been more uncertainty in what people are using. I prefer the original approach, that is v1.06 demo with sound off, booting directly into DOS with few drivers loaded, no EMM386, or mouse drivers, etc.
Plan your life wisely, you'll be dead before you know it.