On the pros side, NEM has had its separate blockchain from the start. It has a solid technical foundation (built in C++ and java totally from scratch).
The only thing that confuses me is the small trading volume among the top 20 (not including tezos)
Not overly large liquidity can mean two things, either the holders are confident it NEM's future and are not interesting in selling, or the demand is low. Low demand can also leave some room for future expansion if or when NEM becomes more popular. On the cons side, they have bad marketing and no real business collaborations. All in all, hard to give a definitive judgement, but this is one of the crypto-currencies one should keep an eye on.