I find Navionics to be far superior to Lakemaster in terms of coverage, accuracy and detail but that's just in my area out west (live in Las Vegas). Follow the contour is a great feature on LM, as is the lake level adjustment and depth highlight, if the lake is supported, and if it is accurate. But it's not much of a stretch to just lay down a route or waypoints on either card's chart and follow that with iPilot link if you have that feature available. The best feature of LM is adjusting the lake level, but again, that is moot unless the chart is accurate. I have both cards and use Navionics where LM doesn't have accurate coverage (which is often). I would say to anyone, unless your LM lake is listed as HD, think twice if you can only choose one card.