Without getting in to which is the better, I will say that I found Flex a doddle to learn, whereas I just can't get my head round XPages. I guess it depends how you like to learn. I like to just open a blank "page" and get stuck in. With Flex (and the aide of demos and help files etc) this is not only easy but a pleasure too. With Xpages I just find myself staring at the blank page for a while and then giving up in frustration.
Without getting in to which is the better, I will say that I found Flex a doddle to learn, whereas I just can't get my head round XPages. I guess it depends how you like to learn. I like to just open a blank "page" and get stuck in. With Flex (and the aide of demos and help files etc) this is not only easy but a pleasure too. With Xpages I just find myself staring at the blank page for a while and then giving up in frustration.