That is a good question Ranger. I have been doing a lot of research and only care about 2D as well. The RS40 will be brighter, but has bulb dimming issues based on what I have found. The RS25 has better controls for calibrating and is more "stable" in the bulb department. I have been checking out there eBay store and if the RS25 was the same price as the RS40 refurb I probably would have already bought one. Keep in mind that the RS25 is *new, not a refurb. I contacted them to confirm this and that's why they changed the verbiage on the RS25 to indicate the standard bulb warranty information. Look at the RS40 and it will indicate something about being a refurb.