Jack is still very a very commercial format, so while you're hearing a variety of genres, it's still top 40 hits from those genres, and usually a limited variety of non-threatening genres.

College radio (that is, radio stations run by colleges with their students as staff) is probably much closer to UK radio than anything Clear Channel is likely to promote.

Edit: I guess Jack is actually Rogers Communications, not Clear Channel, but the devil goes by many names.

Re-edit: You can take a look to see what a Jack playlist looks like. I'm sure you will be unimpressed.