Yes it's definitely different now. 2 or 3 years ago it felt like nearly anything written on HP would rank high very quickly, even a lot of the crap.
There are a lot of reasons why things have changed and the main ones in my view are:
With Google's Panda algorithm 1st launched in Feb 2011, Google completely changed the ways it assessed both page quality and site quality. Hubpages reputation was damaged because it had allowed so much rubbish to accumulate on the site and the site lost a lot of visibility in the search results. HP have been trying to reverse that for the last 2.5 years. http://searchengineland.com/google-panda-two-years...
There was also the Penguin algorithm released by Google in Apr 2012 which targeted spam backlinks. Anyone using aggressive linking practices to rank their hubs higher would have had their pages/subdomain penalised by this one.
The other main reason is to do with the weight that google gives website authority and trust. Hubpages articles are now finding it hard to compete in certain niches and they just don't make it anywhere near page 1 or 2 of the search results for particular phrases. For instance, articles on page 1 for something like "cancer treatments" are far more likely to come from authoritative sources (which is really as it should be), rather than a user generated content site.
Therefore, careful topic selection is much more important nowadays. There are some things that can do well on HP, and some that just can't.
There was also Google's freshness update in Nov 2011. For some types of search queries, google prefers to display newer pages over older ones. Again, this impacts the types of topics that have the potential to do well on HP and writers need to make sure they're not writing in a "fresh" topic area by doing a bit of research before they write.
Personally my account has done ok through the various ups and downs and is currently back to what it was before all these google updates. But I have had to do a bit of work to make that happen.
EDIT: If you want to look at how HP traffic has fluctuated over the last few years check out Quantcast http://www.quantcast.com/hubpages.com