I was under the impression that Sphinx cannot return documents, only IDs. (The implication is that you need to query your data source if you want to show the results.) Is that correct?
If you are looking for caching and other more complex features, I'd recommend elasticsearch (and I do highly recommend it). But sphinx is simpler, and I think it is a good alternative for the type of functionality talked about in the blog post. Granted, I really don't think elasticsearch is all that complicated either, and it is also really well documented. But sphinx is just painfully simple for the basic use cases (like anything postgres can do).
As ever, it's a tradeoff. I used to keep everything required in for search results pages in the search index (solr, at the time). Eventually I decided that the additional db lookup was well worth the extra few milliseconds to make sure I was working with reliable data.