I really like #433, and would like to see a few more variations before I make a decision. Can you come up with a way to tie the image into the logo? Also I would like to see the font be a little bolder so it stands out more.
In addition, or another variation, maybe bring the building down a bit (or maybe 3 smaller buildings) and give the palms a little more detail. Plus.com needs to be larger, and maybe all upper case letters. Thanks