I'm also not exactly sure why that comment is in there. What I do know is that the 4 AAA batteries (the cheapest I could find) have now lasted the equivalent of about 2 race meetings in my EX-2 and still going at 5.1-5.2v. The EX-1 is more energy efficient according to the spec sheets, so you should be good there
In addition, the EX-2 has an inactivity timer to prevent draining the battery; it's fixed at 3 minutes for the EX-2; the EX-1 also features it, although it might actually be adjustable.