This is a neat little unit that feels well made. The mounting system is easy to use and it's small enough to throw in a pack so it can be snapped into place for the trundle home after late-finishing trail sessions. And that's what we'd keep it for - the last half an hour after the sun has set, or as an emergency backup.
The light lacks power and is too torch-like and restricted for serious trail use, although if you're absolutely limited to under £100 then the Topeak Whitelite does have a more versatile beam for trail use. But if it's a low-cost, small pack size, urban commute light you're after (and for relatively short distances or you're gonna burn through the batteries) this could fit the bill.