It depends on what you want from the casefiles. If you want exotic, over-the-top, world-ending, and unbelievably weird (as you get in most casefile shows these days), you will be disappointed. Elementary's casefiles are odd and tough to figure out, but in a believable way (except for one, which still wasn't as ... theatrical as the most ordinary BBC!Sherlock case). It's not that the police couldn't solve these cases, the cases aren't that unbelievably fiendish. It's that Sherlock will spot and work through things a lot quicker, and go off on a tangent to get other stuff while the police are doing a lot of the basic policework and so catch the killer much quicker. That's another thing I like about it--unlike BBC!Sherlock, the show recognizes that modern police have things like forensics and stuff, and are actually competent. And we get to see them being competent (though not brilliant) at their jobs. And we get to see Sherlock be wrong a few times an episode as he works through the evidence, figuring out theories and discarding them as he and Watson and the police work through the evidence and figure out whodunnit.