Everyone does this backwards.
First, write down your requirements. What do you "need" to do. The list should be fairly exhaustive. Then make a list of nice-to-haves.
Now see which product addresses the most items on your need list. Even if you don't have the product, odds are someone has already asked about every feature on your list. So just search these forums. If X9 and X10 are a pretty close match, then see who covers most of you nice-to-have list.
What this does is it forces you to know what your want and what you're going to do. Most people here just make it up as they go. And guess what. They never finish their game. Or they just complain about FPSC. This is also because they bought something that never did what they wanted, but because they didn't make a list and compare, they bought it anyway and were disappointed. It's like buying a new part for your car and hoping it works without checking the make/model/year (requirements). If you don't have a car, it's like buying Mac software to run on your PC. Know your requirements!
(We're under a blizzard watch today. Great day to work on a game!)
"I'm trying to find new ways to make this game more attractive." - Dennis Rodman