Originally Posted by Michel Gagnon

I have looked and tried an EL-410. My trial was in the shop, wiith my own Beamer 5 in hand for comparison.

How do they compare?

With fresh batteries, I think the total light output is roughly the same.

EL-410
The EL-410 throws all the light in a tight circle, so it's best to light things far away. But in a totally dark environment, I would prefer a bit of stray light on the ground too.
It has a translucent ring all around, which gives side visibility. I would put electrical tape on the top to avoid partial blinding from that.
It is said to be submersible (dixit Cateye), which means it won't stop working if you ride in hard rain.
The "clamp" is very ingenious as it works on almost anything. But I didn't feel it was as secure as the clamps used on Planet Bike lights.
It uses 3 AAA batteries, so it's not rechargeable-friendly.


Beamer 5 (sorry, I did not experiment with the 3)
Like most Planet Bike headlights, it uses 2 AA batteries. So if you get rechargeables, you can charge them in pairs.
It resists to midst or to a short rain, but not to 2-hour downpours. So my Planet Bike headlights now live in a plastic bag.
Illumination: there is a centre spot and four accessory ones. Overall, it means less light in the centre than what you would get with the EL-410, but also some light close to your bike wheel to help you see potholes.

Conclusion
Though both would offer you visibility, I think the Beamer wins by a tiny margin because it's more visible than the EL-410 off-axis.
Amongts these two, I might prefer the Beamer 5 for city riding, and none of them by themselves as your sole lighting source.
But to further my recommendation, I would suggest the Planet Bike Blaze: still 2 AA batteries, rugged construction, but with a better beam, especially on the road.