Let me go over the cons and pros and maybe you can decide for yourself

cons

• it has less freedom than photoshop
  
• initially some buttons may not be clear
  
• the system slows down if you have it open for a long time (for me that's 5 hours or so but I've heard 3 and 4 as well)
  
• group rotation can be iffy if you use the horizontal or vertical mirroring
  
  • making a world map is possible but requires finessing to really make it look good. It becomes pretty obvious it was built for making dungeons originally.
• isn't updated regularly

Pros - quick way to make a good looking dungeon.
- no need to set up a grid or slowly trace walls - lots good looking objects and other textures that can be placed hassle free. - mods for even more objects, floors, and walls - simple to use effects to make things pop more. - has a useful search function which has additional uses. - many many styles. - the crathography is really fleshed out. - can always add your own objects. - designer listens to the people who use it.

I think it is very useful, but lacks some... depth I use it in combination with photoshop since the objects can be a downer to place.

But it's probably best if you make your own decision in this case.