I have both the one-watt Blaze and the 5-LED Beamer lights on my bike (note that I am comparing the one-watt Blaze, not the half-watt Blaze). I use the Blaze for constant-on illumination (to see) and the Beamer as a blinker (to be seen).
First of all, there is NOTHING WRONG WITH THE MOUNT (which is the same for both lights). Please ignore other reviews to the contrary, which were posted by people who are apparently unable to read an instruction sheet.
The mounting strap is ADJUSTABLE. It will accommodate very small handlebars, as well as massively oversized handlebars. If you turn the mounting bracket over and examine the underside, you will see that the mounting strap has ratchet-teeth. There is a keep directly beneath the mount which holds the strap to the desired length. If the mount is too loose, push the strap towards the mount to ratchet it to a smaller size. If the mount is too tight, use a small screwdriver to hold the keep up as you let the strap out. The mount may be further adjusted by turning the set-screw (by turning the cam-lever). Don't make it too tight, or it will be hard to adjust vertically.
The mount is very secure, yet the lights are easily removed (and can easily double as a flashlight when needed - and you could easily hold it in your teeth for roadside repairs).
Photos of both the Blaze and the Beamer look rather similar - I wondered if they used the same plastic housing. But the Blaze is substantially larger than the Beamer (in both length and diameter, even thought they both use the same size (AA) batteries). As I said before, the mount is the same.
In blinking mode, the Beamer is actually brighter (overall) than the Blaze. This is because the Blaze (wisely) does not flash at full-intensity all of the time (otherwise you would absolutely blind passing motorists). The Blaze mostly flashes at low-intensity, but every sixth or seventh flash is at high-intensity. The Beamer flashes at maximum intensity with each flash, which is brighter than the Blaze for most flashes, but not as bright as the occasional max-flash of the Blaze. Overall, the Beamer is brighter in flash-mode, although I am not sure it is better. But it is sufficient for my needs.
Many bike lights are designed like flashlights, where the beam is really visible only from the front - someone viewing from the side would not see any light from the bulb itself (only the things that the bulb illuminated). Both the Blaze and the Beamer have lens bezels which fully expose the bulb to aspect view, giving these lights about 210-degrees of visibility.
In steady-on mode, there is really no comparison in lighting intensity. The Blaze has a high and low mode for steady-on, while the Beamer has only one steady-on mode. My comparison is only using the Blaze in high-mode. The Blaze's intensity is why I give it five stars (I gave the Beamer only four stars because it was lacking in comparison).
The Beamer's steady-on mode is rather hazy and unfocused. The five-bulb light source can be seen in the uneven lighting it produces. The Blaze (which has a single bulb) produces a much whiter and brighter light which is highly uniform. I'm not sure I would recommend the Blaze for absolute pitch-dark riding over difficult surfaces (such as singletrack wilderness and mountain trails), but it is perfectly sufficient for fill-lighting in urban commutes, with occasional very-dark spots. The Beamer is sufficient only for urban fill-lighting - I would not want to use this light in very dark conditions.
If I found myself riding an extended bit of pitch-dark road, I would reconfigure my lights to use the Blaze as a distance light and the Beamer as a close-in light.
Some posters complain that NiMh rechargeable batteries are inferior to alkaline. I am not able to discern any difference in the Blaze. NiMh batteries are 1.2 volts, whereas ordinary batteries are 1.5 volts. However, it is not really voltage, but milliamp-hours (mAh) which determine a battery's power potential.
The Energizer e2 MiMh batteries can be charged to 2,450 mAh (milliamp-hours), while fresh Energizer Alkaline batteries are rated at 2,850 mAh.. So the difference in power is about 8.75%. I cannot perceive this difference. However, a freshly-charged MiMh battery will ALWAYS out-shine a somewhat-discharged (but still relatively new) alkaline battery. There is a temptation to use disposable alkaline batteries until they are absolutely worthless - thereby depriving ourselves of good lighting (few people toss out batteries because they are only at 91% power - the point at which fresh NiMh batteries exceed their 8.75% discharged alkaline counterparts). It is better, IMO, to have a slightly inferior battery that I can recharge each evening, so I always have an absolutely fresh battery, rather than a disposable battery that may be slightly brighter for the first hour or two, but soon looses ground to a freshly charged NiMh battery.