So I have not yet run the actual game with my players yet. However I did some quick testing last night to see if this app was going to work for running the game from. Here are my findings:
Player view needs some more control. If I want to display a tall map, there's no way for me to rotate the player view to make this fit the screen. If you are using tokens this wouldn't be an issue, however when you are trying to get the zoom to fit in such a way that the players can put physical minis on the screen, this becomes an important feature. In a worse case scenario I could just crop the long portion out of the larger map and rotate the image before importing into DM helper. However if would nice to just be able to upload my mega dungeon map and do any tweaks within the program.
The rotate function would also help, as my players are sat around a table, so if I'm displaying an image of an NPC, or text I want them to read, the ability to rotate the image to make it easy to view for each side of the table would be nice.
The encounter builder seems really reliant on the use of the in game tokens and the built in LOS/FOW features. Since I don't plan on using tokens, but rather my own miniatures. it would be nice if I could just edit the fog of war manually during encounters, rather than having to do the fog of war stuff in the maps window, and then just keep hitting publish to update it.
The initiative tracker is great.
The bestiary is great
I love that I can publish photos of the monsters and NPC's to the player view, rather than just battlemaps (without having to trick the program into thinking the pictures of NPC's are battlemaps).
I would love to be able to have adventure specific NPC's rather than all NPC's going into the "Setting" category. I often have one-off NPC's that are important for an adventure then usually don't return, but might.
I will probably be back with more stuff after I actually run the game with my players. As a planning and running tool this app seems awesome. Running the maps on the table is the big draw for me in using this app, so whether I continue with it or not all depends on how quick and easy it is.