IMHO, it isn't the compatibility difference from 040 to 060 to be the issue. You can always Disable the CPU. It is all to do with the card the chip is on. The 3k will give you issues with some games period, 32 bit bus, 2.04 and up, etc... You can play with lots of the settings, but if it was designed for 1.3 on a 500 it will be a challenge...
An 060 in a cyberstorm versus and 040 in a warp engine, told an interesting story. I tested both cards in 2 similar systems at the same time. An overall experience of a faster system went to the warp engine. The build in SCSI on the WE certainly made up for alot of that experience. If your going to ray trace, then go with the 060... other than that, hold out for a warp engine for the 3k, it is the best choice...