I would say the upgrade to DX10 would be worth while as there are no soley DX9 cards being sold today. While all video cards sold today can do DX9/10/11 10 would be the best bet as DX10 cards have been out for like 3 or 4 years (atleast) now and most people have upgraded. HELL Even integrated graphics cards can do DX10 now.
I am just wondering. is anyone still running a video card that can only do DX9 anymore?
(i know this is off topic but other people were talking about stuff like this)