Does Anyone Use Dedicated Servers For Their Blogs Or Authority Sites?

I'd advise against it unless you have the experience to configure, maintain, secure & fix problems that come up. We do lots of migrations from DO and the bulk of them come over with hacked WordPress sites all the time. Without naming any products, most of these "installers" built around DO & Vultr aren't properly securing the servers and certainly aren't ensuring the websites themselves are secured.

To your original question, it really depends & when it comes to both VPS's & dedicated servers, it really depends on the underlying hardware. In terms of cost, you'd likely be better off going with a larger VPS which you'd be able to get more resources for your money. Of course, if the host managing the hypervisor isn't doing a good job, you can still have problems just like you can with a poorly managed/configured dedicated server.

You'd really want to get an idea on your "resource" usage in terms of RAM, CPU & disk I/O usage and calculate and estimate based on that. 300K monthly visitors isn't unheard of for even shared hosting (of course a good quality host) but it still largely depends on the site itself - size of site, size of requests, database driven, proper optimization etc.

the term "traffic" doesn't really equate to anything to justify using one option over the other - you need to have an idea on resource usage. You could have a million visitors and use a small amount of bandwidth but have a high RAM usage or the other way around.

These days I think a dedicated server doesn't really provide a great bang for the buck. If you've got the technical know-how, cloud-based hosting offers much more flexibility at a much better price. We currently run seven instances on Amazon Web Services for about the price of a high quality dedicated box. Perhaps we pay a little more than we might on a dedicated box, but for our money we get (a) flexibility and (b) Amazon.com's top engineers running the network and the physical hosts that our instances run on. (I should also note that though we use AWS, there are plenty of other top-notch cloud providers out there!)

Thus, if we have a spike in traffic, we just add more servers to the mix -- we've had over 20 running at one time. Then, when we don't need them anymore, we just terminate them. The problem with a dedicated box is no matter what your traffic level is, you have a limited capacity. This might not be a problem if you're traffic profile is pretty even over time, but if you're like us and have huge spikes, it's far from ideal. Another problem is that your physical box is a single point of failure. So if it goes down, you're screwed. On the other hand, if one of my web servers goes down -- or if the physical server on which it resides goes down -- I just terminate it and let a new instance take its place. You can also split the load more evenly wherever you might have bottlenecks. For instance, if you have a CPU-intensive web application, you can add more web servers. On the other hand, if you do a lot of database reads, you can add some database read replicas pretty easily. And they all function independently, which is really, really nice.

All that said, if you don't have good systems administration skills on your team, you might find it challenging to manage a bunch of instances -- though in that case, I'd question whether you'd be ready to manage a dedicated server too. And regardless there are more and more companies getting into the "managed cloud" space, so perhaps that's not even as much of an issue as it used to be.

But whatever you do, good luck!