Depends. If you're not interested in fiddling with power, then essentially unlimited fuel makes it easy to set up a reactor, automate fueling and go about doing other things. Limited fuel forces you to consider reactor efficiency, cooling and up-time, as well as impacting design choices for builds. I consider the latter more interesting, and what I'll be doing in my next 'normal' world. Currently, however, I'm playing Agrarian Skies, and I just built a 'MOAR POWER' reactor, because I have other priorities, lol.