From what little I could dredge-up, the main issue is brake-clearance regards using a 32C tire:
http://answers.yahoo.com/question/in...4211225AAI1QL1
I did find chatter complaining that Alex rims won't answer emails and they tend to go out of true quickly - and stay that way.
This
could be another example of how the bicycle industry has been cutting costs by supplying low-quality (cheap) wheels with their bikes.