The XR-E LD20's (Q5's and R2's) were rated at emitter lumens. Between not having a 100% reflective reflector and lens losses, a good rule of thumb is about 20% loss from emitter lumens to out the front lumens.
The Ra will do 140/170 for 10 seconds, then have a slight (as in barely perceptible) drop to 100/120 lumens. They will then do that dead flat output for at least an hour, before gradually stepping down to lower outputs over the course of time. Realistically, because the Ra's have constant output, versus the gradually dimming output of most other lights (in which runtimes are rated by a drop of 50% of output), the Ra is much more efficient, and uses a cell more efficiently.
I would also suggest the Ra140. The extra step from 100 to 120 lumens continuous is not worth the money, unless you really want the higher output and greater efficiency of the 170.
The wide or narrow beam pattern is entirely up to you. The Wide uses a Seoul P4 LED, which produces an incredibly smooth hotspot-to-spill transition. The Narrow uses a Diamond Dragon emitter with the same reflector, but focuses slightly tighter than the wide. It doesn't have an extremely tiny, laser-like beam, but instead has a nice, intense hotspot surrounded by a medium intensity corona, and a nicely illuminated spill. My 140 narrow easily throws 150 feet in an urban environment, with lots of other streetlights, etc.
The Ra's also have automatic rechargeable battery detection and protection, to keep a Lithium ion cell from being over-discharged and therefore damaged.
Henry (the owner) also has said that 2 AA battery compartments will be available soon, meaning that you could have a CR123/RCR123 battery compartment, for EDC, a 17670 compartment, for longer runtimes, while using Li-ion cells, and a 2AA tube, for the ultimate in versatility, and cell scrounging.
The Ra's are some of the most durable, user friendly, user customizable lights on the market. Their build quality is on par with Surefire, as is their customer service and support.
The User Interface can be set up to your standards. Each of the four modes can be changed in output, or have any of three strobes programmed in. You can set it up so it always turns on at a certain output, or remembers what setting it was on last. If it gets set in the bottom of a dark tool case, you can set up the locator flash, so that it's easy to find, without draining the battery. You can set it up so that it will activate only as long as the button is pushed (momentary), which will work on any mode (if memory is enabled, by disabling "force" setting). The booklet it comes with makes it seem intimidating to program and use, but I was able to learn it within 20 minutes when I was half asleep, and can now reprogram it at will, from memory.
The lights are waterproof to 66 feet, the glass lens is 3mm thick, and protected on both sides by O-rings, so no worries about cracking it. The battery is protected from damage by springs on both ends, and the electronics are fully potted, so no worries about damaging it. It has Hard Anodizing level III, which is, if I remember correctly, as hard as diamond.
