I'm a Wordpress guy to the core. Everyone knows that. However, recently I've started to migrate some of my sites to Squarespace, including this one. I've realized that as I get busier, a perfect Wordpress site becomes less achievable. Anyone who knows anything about customizing a Wordpress site knows that it take a lot of time to get it right. See, it even rhymes.
This is probably the biggest advantage to moving to Squarespace. In order to keep your WP install safe, you have to continually update core installation, as well as all of the plugins. Anytime you update anything, you're at risk of breaking your theme or elements of your site beginning to look funky. For instance, let's say there is a particular theme that is designed for the version of Wordpress you are currently running. A new version of Wordpress comes out, and in the release notes, you see that there are some critical security patches. Great! Let's update! But wait, now your theme looks like complete garbage because there were other coding changes that caused the theme to break. Not to mention all the plugins that are probably now worthless. Now you've spent all day updating your theme and/or rolling back your sites (crossing all appendages hoping that you have backups that are intact).
And the plugins. OH, GOD, THE PLUGINS! Isn't it ironic that plugins are one of the strengths of Wordpress, but when things go wrong and you call support, the first thing they tell you to do is disable all of your plugins? Plugin are awesome, but between SEO, speed optimization, image crunching, CDN plugins, slider plugins, and all that other great stuff, things can get out of hand really quickly.
It's Not That Expensive
You may think so but you haven't seen my AWS bills. Trust me, Squarespace is cheap for the peace of mind. It's $12/mo. if you pay annually. You never have to worry about server health or any of that crap. At one point, I had to convince myself that I am not in the server management business nor do I ever want to be. Nothing beats the prices that you get for Wordpress hosting, but you'll get a lot of time back, and if you're like me, many a sleepless night, too.
It's Squarespace's job to keep your site up and safe. Their sites are not prone to the same brute force attacks you'd experience with a self-hosted Wordpress install. Of course, there are probably a lot of plugin options to ward of brute force attacks on WP, but as mentioned earlier, that's just another plugin you have to worry about.
I just tested 3 sites: this site, which on Squarespace, a Wordpress site on AWS (which I pay a lot for), and a site hosted on GoDaddy's Managed Wordpress service. I tested for server response, because in this case, all 3 sites had different amounts of content, so it doesn't make sense to line them up that way. Anyway, this site had a server response time of 233ms, AWS was at 855ms, and GoDaddy clocked a whopping 3.06 seconds!
In other words, Squarespace blew everyone out of the water speed-wise. That leaves you to focus on the content itself and make sure you are compressing images before uploading them.
That's all for now. Let me know if you have any questions.