the main problem with DX10 is not the "vista only" which is already an issue.
The main problem is that more than half of all sold Vista machines are NOT DX10 compliant!!
Intel GMA 900 / 950 are Vista capable. Not DX10 compliant. But sold in Vista boxes
Intel X3100 is DX10 compliant but 3 frames with ultra ugly graphics settings makes it non compliant in my eyes
ATI / NVIDIA onboards: not DX10 compliant as well
So by using DX10 you seriously cut it all. If you want to go that route you can as well just invest in the S2 or LeadWerks engine, they cut the possible user amount at least by less than that by "only" enforcing SM3.
The main problem is that more than half of all sold Vista machines are NOT DX10 compliant!!
Intel GMA 900 / 950 are Vista capable. Not DX10 compliant. But sold in Vista boxes
Intel X3100 is DX10 compliant but 3 frames with ultra ugly graphics settings makes it non compliant in my eyes
ATI / NVIDIA onboards: not DX10 compliant as well
So by using DX10 you seriously cut it all. If you want to go that route you can as well just invest in the S2 or LeadWerks engine, they cut the possible user amount at least by less than that by "only" enforcing SM3.