The first thing to consider when choosing a circular saw is whether you already have any cordless tools from either brand. Nearly every modern tool manufacturer has its own battery system. These batteries are typically categorized by their voltage output. Many tools of the same brand can use batteries interchangeably, so long as they require the same voltage. For this reason, it’s usually a good idea to stick with one brand of wireless tools. It allows you to invest in a single battery ecosystem, and you don’t need to fill all of your power outlets with chargers from different brands.
That said, Makita and Ryobi’s batteries are slightly different. They are both 18V Lithium Ion batteries, but Makita’s LXT battery system has a reputation for being one of the most sophisticated on the market. TheSawGuy reported that LXT is more efficient, more reliable, and tends to have a little bit more longevity. It uses Star Protection Computer Controls to protect against overload, over-discharge, and overheating. Their saws also have a built-in fan system to keep motors and batteries cool so that they last longer. The LXT batteries also work with some of Makita’s really strange cordless tools which most other brands don’t produce.
That isn’t to say that the Ryobi One+ system is bad. Many users have found it more than sufficient for their needs. But those who intend to put in long hours of cutting without recharging their batteries might be better off with Makita’s LXT.