You will need to think about the type of riding as well as where you will be cycling.
Are you riding at high speed or at a leisurely pace? Will it be well-lit or dark where you're cycling?
If you're riding at a low speed and it is well-lit, you will mostly just need to be seen by other motorists, cyclists and pedestrians.
So you can prioritise lightweight or low cost versus brightness.
However, if you intend to ride fast, and will be in dark areas, you will want to invest in a light that can help you see where you're going, but costs more or is slightly bulkier.