We sold a lot of MaxSea software over the years and I have to say that my experiences were all fantastic.I haven't encountered a chart problem with MaxSea (or MapMedia or NN3D) but did come across some software issues. Support from MaxSea direct (i.e., France) was excellent.
Much of the US support is handled by Furuno. When there was a question that we couldn't handle, we'd refer the user to them. Whenever I heard back, their experience with Furuno support was out-of-this-world great. Those guys would walk them through the issues and fix the problems. It was very rare that something didn't work and I can't think of many times when I went back to France myself with an issue. If the solution couldn't be arrived at, we'd always refund the purchase and MaxSea never had a problem with that.
I think that MaxSea is a wonderful and capable developer. We're lucky to have so many great choices in our boating world.