Cool, I like the new tiles. I think that ground texture is too saturated, but I can change the texture later. Here's a long list of suggestions (many in attached images):
1. The trees are grouped together with similar trees too much. Ideally all the different kinds of trees/bushes should be spread around the whole map so that it looks like a diverse forest. One of the attached images shows how I would re-arrange one of the tiles. To do this right, you will need to edit the existing tiles as well. My recommendation would be to experiment on a very large tile (mabe 1024x1024) to get the right mix of trees/bushes, and then try and replicate that mix across all the tiles.
2. I like the smooth hills you've put in. I wish there were more of them and larger ones. Right now they're just a lump sticking out of an otherwise flat surface. It would be great if you had large hills across 512x512 or even larger, rather than packing them into small little mounds. I think it will make the map a lot more tactically interesting, and will remind me of the good ole X-Com hills.
3. There's an image showing a rectangular rocky outcrop. I like the idea of having a different texture up top, like grass, but the rocks are too rectangular.
4. In another attached image (next post), you can see that the tree shadow gets cut off at the edge of the tile. This is another reason why larger tiles can be better than smaller tiles. For instance, if I had to fix this in the repository, I would not want to have to open 50 tiles to figure out which one it is. With so many very similar tiles, it will be a real pain to maintain.
5. I highly recommend you don't rotate the ufo like you have with the fighter. First, you're missing the weaponclip brushes for it so those would all need to be recreated or imported and rotated to match the UFO exactly. Second, you end up with tons of wasted space around the ufo, places where the player feels like he ought to be able to go but can't. All of the UFOs are designed to fit in with the tile system, and they don't fit well at an angle. And third, you have some places in the UFO where a soldier overlaps the UFO's walls.
6. I like your new building, but the roofing kind of looks like you just got tired of it. I drew just a few lines to suggest more interesting roofing and a deck.