The Ayups are good value because they are simple. They are just a light and a battery (and on recent models a switch).
Where you lose is on flexibility. If you want it to last longer, you need a bigger battery (or another one). More expensive lights offer the option of turning down the brightness for longer life, which is quite handy when you consider that on a straight and even track or road, you often don't need all that much light. You get to either ride for longer or carry a smaller battery for the same functional benefit.
In terms of light output, the actual LEDs are pretty much standard for recent lights, so you can compare lights just by counting LEDs and looking at full power run times. Eg an Ayup (with 2x1 LED heads) will give much the same light as a USE Exposure Race Maxx, or twice as much as a Dinotte 200 or Ixon IQ. You just have to watch for models that are still using last year's LEDs.
There will be variation in beam pattern (narrow, flood, shaped), but you really have to see the light in action to judge that.
so I contacted ayup uk and they sent a replacement straight away (one of the new types with an on/off switch).
