Wow Bryan..... you're opening a huge can of worms here. I can't speak for anyone else, but I am SURE that I could find at least 10 ways to benifit from the added features in the 2k over the 740.
For starters:
1)sound system - no contest
2)vocal processor - no contest
3)sounds - HUGE improvement in some ares
4)navigation - large screen
5)insert effects ....

I'll stop at these 5 and leave room for some others who " don't use a tenth of what's available on their keyboards.."

I, for one .... use EVERYthing I can in each keyboard I buy. That 10% comment was a little underestimated, I think. If you read these post alot, you'll learn alot about how others use these instruments to make life on stage much easier !