I'd really have to dig into a working example to assess the UX but, judging from screen caps, it looks great!
I can see how topo would be very useful in certain instances. To @user5684858 point, be mindful of how well your markers separate from all that detail. You might try a slight border on the circles to ensure that they contrast varying backgrounds.
The presentation of the table is a little weak. I'd consider some chrome to make it a little more readable/engaging. Is there any data in there that deserves attention: outliers, mean, etc.?
In the messaging feature, if you use relatively large avatars as shown, I would allocate a little more space for the recipient list. A non-scrolling presentation could work if these lists are likely to be terribly long. Google Plus' implementation of adding people to a circle comes to mind as a good example of this.
It appears to me that your two blues (the header bar and the blue tints used in the body) are not working very well together. They're close but the hue is off slightly: the header moving toward green and the body toward purple.