Bitcoin is still the numero uno at this point but not for long as new better technology is popping up. Monero is not one of them though. It is marketed by a spectacular amount of [enthusiastic evangelists] who claim that it's greater and more innovative then Bitcoin...only difference is cryptonote.
To my eyes, that makes Monero intriguing. Why did Bitcoin rise so much in four years? A lot of it had to do with tireless and enthusiastic evangelizing from Bitcoin early adopters.
To shift back to Monero: regardless of how many of them are "paid shills," if any; regardless of the fact that they obviously have a pecuniary motive for promoting Monero, as I'm sure they all own a lot - their tirelessness and enthusiasm is reminiscent of the "paid shills" for Bitcoin back in its early days.
You, sir, are obviously not impressed with Cryptonote technology. That's really the focal point of whether or not to jump in. Is Monero's implementation of Cryptonote tech - is Cryptonote tech itself - enough of a crypto game changer to make all that indefatigable evangelism pay off big in the longer term? The question don't answer itself.
From what little I know, Cryptonote's signature use case is very different from gen-2 crypto like your NEM. Sure, we can think like bookkeepers and say that one BTC that buys Monero is one BTC that will not go into (say) NEM...but the funny thing about evangelists is that they become good at bringing outside money into the crypto sphere, thus breaking the zero-sum model.
If you're ticked off by what I wrote above, please stop and consider that I'm outlining the thought process of an interested speculator. Any speculator looking over NEM will probably think along the same lines with respect to NEMmer evangelization.