Recent reviews by Primatus Pogonis

Generally a good map making tool, but the Steam Workshop community makes it a lot better. Expect it to work like MSpaint/Photoshop/etc, so a lot of hours might be sunk in making your maps as detailed as possible. Still, it beats searching online for good replacement maps, when you can just build your own.
Good integration tools included for making maps tailored to specific online browser programs as well.