Great to have a bright display - I see Helm claim "over 1,000 nits", which is 2-3 times most tablets. That isn't 2-3 times perceptual brightness, of course, as our eyes have non-linear perception of brightness. You need to increase brightness by 6-8 times in nits to appear twice as bright.
Alas, my budget doesn't run to a Helm, and I use a Tesco Hudl at about 5% of the price and a mere 400 nits. But the GPS works OK.