I used to use this a lot. My experience is that for some reason, a couple years ago it stopped working reliably as a fresh page fetch. Some items were still coming up cached. Now I use incognito or private browsing windows instead.
If you're running Chrom(e|ium) with developer tools open then you can right click the refresh button and it gives you a few refresh options (eg clear cache and reload).
That tends to be my fall back whenever I'm specifically fussed about the "freshness" of a page. That or curl
