I was building a lot of machines back then since there was profit in them. But...
Any I had a DX33 that I ran at 50mhz and it was faster than my friends DX2-66. I sold a guy a Pentium 60 and my dx50 was indeed faster than it. Not a lot but it was faster.
My 50 was so much faster than my friends 66 that there use to be this thing called 3DBench back in the day. any way with an ISA ET4000 and his VLB something or another that was a much faster card we would run about the same FPS.
Mine however could start WindowsNT 3.1 almost 40 secs faster with the same drives and memory.