Great map, wonderful design, good colors.

Photoshop might be slowing down if you have to many layers, If you are happy with how it is looking, try flattening some of the layers.

My only complaint is that while you did this at a nice high resolution, the size is way to small to be useful for printing at battlemap size or on a VTT system.
The map would need to be at least twice as large for VTT and 3 to 4 times larger to print at 1 inch = 5 feet size. Most of the time I make my maps at 100dpi 1 in = 5 ft, though sometimes I will do even higher resolution.