I've used Flickr for over 10 years for photo hosting and have no real complaints. I've got over 4,200 photos in albums, all tagged, and most with geotags also. It's great when someone asks "Do you have a photo of...".
My reason for looking for another hosting site is for selling and to relieve me of manually printing and getting images to people. I get normal requests for shots for websites, magazines, etc, and SmugMug (among others) has the watermark overlay feature which I appreciate, but gives the option to download the file at a price I set and they get the full res image, unwatermarked. Flickr is great, but I have LR watermark the image prior to upload, so I still have to go retrieve the file and export it for people when someone buys it.
Another reason, sometimes at local events, there may be several people wanting to buy photos/canvases and it would be easier just to setup the store via SmugMug at my price points and let them handle everything and send me the 80% profits.
I'm going to setup a Wordpress front-end, blog, etc, but thinking about the "portfolio" linking to SM. I'm here looking for thoughts, and want to hear opinions, or other options...