In fact, because you have to set your news servers there is an extra step with nzbs on setup.
For me, I prefer utorrent. After many suggestions here I tried nzb for a couple of weeks. Its okay I suppose but had some serious drawbacks.
Older movies and complete seasons of stuff are way easier to find & download on torrent than nzbs. Utorrent is better for getting through firewalls as well. Its fking easy to lock out news servers.
For the latest series and movies theyre about equal. Both come down at full line speeds and both are well supported. Though to get best results from nzb I found I had to use a paid for service as the IS news servers sucked balls.
However, so far as ease of use goes... theyre pretty even. If I want the latest episode of something I go here: http://thepiratebay.se/top click on the link and thats it. There is nothing complicated about it at all.