Definitely. 500px is the best place I’ve found for getting some sort of response without having to do a bunch of self-promotion. I still only get a handful of likes (like, ten is really good for me, twenty is great), but it’s more than elsewhere and they seem really good at surfacing your pictures for people who aren’t already following you.
I still find Flickr to be my favourite balance between archival and portfolio. They’ll keep full-size JPEGs for free now (not RAW, though), and I like their viewer with its click-to-zoom functionality. Their compression on the resizes is a little more aggressive than I’d like, though, and the dodgy behaviour @Shivoa mentioned is probably worthy of concern, though I haven’t really looked into it.
I have a Tumblr that I originally intended as a more selective portfolio kind of thing, but without the zoom function and with a slightly (though not drastically) restrictive file size limit, I kind of lost interest in updating it.
I really ought to give Amazon Prime Photos a try…