More than likely, they are all going to work about the same as crystal, at least in terms of how the operate from a theoritical stand point. For me, it is how easy is it to suppress fields and rows. If you are looking at dynamic reports, can they be created from code, how are suppressed fields handled, what sorts of data feeds do they use, formula and variables.
I suspect that they are all going to be about the same...last are your users going to be able modify/create their own reports, and I guess support. There aren't many good books on Crystal, and not too many good sites, and Crystal has been around for 20 years. If you don't know how to do something, how easy is it to find help for these other packages.
I don't say that the Crystal is the best, it has is pros and cons, I've worked with Reporting Services, which has its pros and cons. Unfortunately, I think that you have to play with a package to decide if you like it. I don't know if you have the time, but I would suggest taking a more complex report that you / someone has done in Crystal and then recreating it in each of the packages. The one that you like the best would be the one that I would go with....if you have the time.
HTH