Advice on Phono Cartridge

Go with the Ortofon 2M Blue as it's compliance is a much better match for the Pro-ject tonearm that is pretty low mass.  The Denon is way too low in compliance and would result in a unwanted resonance of around 17 Hz. 

Also the Denon is a low output MC and without knowing what phono stage you have, you have to make sure you have a very good one.  Entry level MC phono stages just don't cut it and are often way too noisy (audible hiss) when you need 60db of gain for a LOMC.

The compliance rating of a cartridge refers to its suspension or "springiness" while playing a record with mass bearing down on it.  In this case, the mass is the tonearm.  Years ago most cartridges were high compliance as low mass tonearms (like yours) were the rage.  Today, MC cartridges are in favor and these tend to be low compliance and work better with medium to high mass arms.  At an effective mass of 9.5 grams, your tonearm would be low mass.  The Ortofon has a compliance rating of 20 while the Denon is only 5. 

And the Denon is very low output MC and I would doubt that the built-in phono stage on your NAD would be quiet enough to reduce any hiss.  Assuming that it has a MC setting.

I would stick with higher compliance MM cartridges for your Pro-ject TT. The Ortofon 2M Blue is a good choice for it.

You need to know the effective mass of the arm, the compliance rating of the cartridge and the cartridge weight (add a 1/2 gram for mounting hardware) to determine if its a good match.  Here is a handy link to a tool that will help determine the cartridge/tonearm resonance with regards to its compliance rating...

http://www.vinylengine.com/cartridge_resonance_evaluator.php

You can also google cartridge compliance to learn more about this.

So it is not necessarily true that high end tonearms work well with all cartridges.