Like Behance, Cargo Collective, Squarespace and so on... Tell me what you think!
The further you get into your career, and thus the more work you have to show, the less you need a homemade site. Early in someones career, when they lack a large range of work, having an eye-catching site to make up for it goes a long way. It's a way to show that you can make exciting and innovative work when your portfolio might lack enough examples of that. Later on, when you can show off that you've made tons of impressive stuff, how your site acts and looks becomes secondary, as you no longer need to use it as a crutch to get noticed.
I agree with all of the above. I think, though, that it feels like a bit of a let-down when experienced designers do rely on just their previous work and present themselves in a stock site. It likely matters less to clients than to peers, but I get the impression that what a designer puts into their folio is an expression of their passion for the work they do and so it makes me sad to see great designers seemingly losing passion for presenting their work. There are decidedly some advantages to those sites, mainly that they're networked and give you some cross-traffic from people not already familiar with your work(if you're lucky). I say, do both.
I like homemade portfolios. They usually are more interesting and creative than sites like Behance.
"Homemade Portfolio" is a very heartwarming sentiment. I'll always pour over something designed by the author more than something like the standard Behance scroll. That being said, if you're an illustrator or have a focus on print, those services can be very handy.
You also have designers who have a single page just to present themselves with links to hosted services (like dribbble, behance ...) This way you can have a beautiful personified home without all the backend stuffs.
If you just want to show your work and you're getting enough traction, then hosted service is fine. BUT would recommend homemade portfolio if you know a bit of coding knowledge. Adds that flair and character.
Another thing is the visibility you have with services like Dribbble or Behance that you cannot have with your homemade portfolio (unless you're a web star)
Both, depends on what you're trying to achieve.
If you're looking to really differentiate yourself, then you can design and code (or have someone else do it) a very creative page that represents precisely who you are. Take a look at http://kerem.co or http://www.marcsdesign.com/ for example. Those guys know what they want to show, how and why. Their brand is chiseled deep in the heart of their portfolios.
On the other hand, If all you want to do is to showcase your work online, in case you need to point a potential client over to a collection of your work, then a hosted service can do. After all, your clients come to look at your work, and your personal website is just one piece in your portfolio.
Of course, you can (and maybe should) have both. I am biased, but judging by designers on https://www.scoutzie.com, most have their own portfolios; whether it's a one-pager or a full-blown website, it doesn't matter. But, these same designers list with scoutzie because that's where the clients are.
If you're a novice, you can start simple with a hosted solution and expand later, when you've accumulated enough experience and understanding of your personal brand. If you're a pro, then you already know the answer to this question.