I wouldn't freak out after only two weeks. It may be fine. A few of us felt a powerful difference right away, but for most it took some time to realize the difference.
They are not time-release; that's just a persistent rumor. They do have a thick coating, and some of us quarter (or outright powder) the pills so that the thick coating doesn't make them take too long to kick in.
Many people feel a little fuzziness when they first start naltrexone, regardless of brand. That's nothing to worry about. Did you start with the 25mg starter dose? Some people need time to acclimate.
NoDict has enough concerns and quality control issues that it wouldn't be my first recommendation, but my own pills are NoDict and they work just fine. So do many others. I wouldn't sweat your brand choice too much unless you get through several months with no noticeable change.
If you scroll back through this thread, you'll see the newbie version of me freaking out about having NoDict. I was worked up over nothing.

It was fine.