Good addition Ramah!
I use quite a lot this program and i'm happy to see you adding more personal stuff. I had a look on what you improved and it's great. I particularly like the random variation in the size of the trees, controlled with some settings though. It brings definitely something good.

So far, i've found that the standard brush fits the best and has the better final render. Coniferous trees miss something and the lack of shadow effects (not available at all in fact) for the other trees don't give them the capacity to be on the same level of achievement.
I don't know how hard it is to make new brushes but the thing I thought about, when I was doing ma map, was to try to make more brushes, especially new coniferous trees, palms (for jungle) and even swamps. Then the range of trees available would be even better.
But at this stage, it is just some ideas