For a decent quantizer, I would go with a Disting mk4 ... :)
It is a bit of a joke, because Disting is basically the Swiss Army knife of modules. It does everything, including quantizing (as far as I remember, it has three different versions of quantizers), but it only does one thing at the time, and the interface is not the most accessible, to put it mildly.
It is great though, because it let's you play around with a quantizer, or an LFO, or a slew, or s&h, or logic, or a thousand other things, which help you understand how all of this works. If you find that you always use it as a quantizer, that's a good sign that you need a dedicated module for this, and then you will have a better sense of what features are important.
Just my two cents.
Edit: I just checked. The recent firmware has five different quantizer modes ... :)