Well, I personally will always prefer MOCpages. That is where I started, have grown in building skills, met new people and friends, and have gotten more-or-less well known. Even though MOCpages takes longer to post a creation, I prefer it because in one post, you can have as many picture as you want. On flickr, that just clutters your photostream, since every picture is a post by itself.
I do like flickr as well, since it is so quick and easy, but I wouldn't leave MOCpages, it is a great community, and there are still tons of great people building and posting on there, for instance, Luke Watkins, Simon Liu (he just joined earlier this year for the MocAthalon), Blake Baer, Sean and Steph Mayo, Legonardo, etc.
Yes, I still have a
MOCpages account. I am active in the sense that I compete in contests, judge contests, comment on other people's creations, find new great builder's, etc. I just don't post a lot in groups, like I used to anymore (mostly because I am very busy now).
I hope that you don't leave MOCpages, you are a fantastic builder, it would great to still have you on the site.
~Matthew Oh~