This blog has seldom had many comments. There are times when there are spikes in the number, but generally it’s pretty quiet—as it is on the majority of small blogs.
That’s precisely why the commenting problem was such a big deal: I spent way too much time dealing with spam in order to keep things clear for the few who left real comments.
For that reason, the new system has been an unqualified success: Not a single spam comment has been posted to the blog since I switched to the Disqus system. Such comments are still sometimes posted directly to blogger, but I don’t think there’s any way that an ordinary person would see the spam comment or two that still get past Blogger’s inept filters (the two systems, technically, run in parallel) because I changed the HTML code for mobile devices; until I did, mobile devices bypassed Disqus and were the only place such comments appeared.
However, there has been one cost: People who use old web browsers can’t leave comments because old browsers can’t utilise features like Disqus. While being able to comment is good, it’s perhaps not the best reason to keep web browsers up to date: Security is.
All browsers have some security vulnerabilities, most of which are fixed by periodic updates. However, there comes a point when a new browser version is launched and, eventually, support and updates for old browsers ends. When that happens, old browsers leave the user's computer vulnerable.
The second-best reason to keep browsers up to date is that they can then use all the features of websites (including Disqus and many more). No web developer supports all browsers ever made—it would far too expensive to do so and, in any case, it’s impossible to make some features backward compatible.
So, for me this new commenting system has accomplished exactly what I wanted it to. Most commenters can use the new system easily enough, and those few with old browsers who can’t just might be spurred on to finally update. In that case, we’ll all win.