I bought the all-black ones. They're awesome. They feel great. They're great in the woods and on the ground. They might not be perfect for tree climbing.
First of all, there is no use for these things for "tabi-style footlocking." They are too soft and flexible. Footlocking demands some stiffness in the sole, and these don't have that. No, if you want that, I have seen the future of footlocking, foot prusiks, and foot ascenders, and that future is the >>[url="http://gear.sherrilltree.com/iwwidb.pvx?;multi_item_submit?comp=SHE"]Pantin.[/url]<<
But back to the Vibrams. The soles are perfect. You somehow feel everything, but none of it hurts you. You can step on a big ol pinecone just fine. I got a little foolhardy and walked across a 100' fallen poplar over three streams, and the flexible soles and individual articulated toes did help keep my balance. I felt like I belonged in a circus.
So I zig-zagged about 40' up a dense magnolia with lots of close branches starting at ground level. I modified some socks, because the shoe uppers don't cover enough, and I don't want the tops of my feet hitting poison ivy on the way up. It had just rained that day, and on damp ground these things WILL get soaked. They're very breathable, though. They are lined with some kind of microsuede, the stitching is simultaneously invisible and unbreakable, I abused the stew out of these, and they stood up just fine. They can be machine washed cold and drip-dried. And if your feet are clean when you put them on, the insides will still be clean after you take them off unless you get them soaked in mud.
Back to the circus part. You will look like a FREAK in these. 25% of the people who see you wearing these will get it immediately and demand to know where they can get their own. The other 75% will look at you like you just coughed up a live frog. Either enjoy it or avoid it.
The Vibrams came in "handy" (heh) that day when I had to reach for a dangling hammock lead. But mostly they felt much more welcome on the ground. Walking on jagged rocks by a stream is probably the ideal use for them. The feeling is addictive.
The sizes run big. Buy at least one size smaller than you normally buy if you do buy. You might not end up using them for tree climbing, but you will wear them when you get the chance. You won't be disappointed. They have a great product, and pretty soon you'll see them popping up everywhere. They'll be as household a name as Merrill or Keen.