I used it on my 20 gal. long. I liked the way it looked in the planted tank. I have pictures of it somewhere.
The wood does take quite a bit of time to sink. About 3 months later, I started having problems with it. Fungus started growing on it, and my fish started behaving odd. I noticed that they had cotton mouth, so I immediately threw the grapewood out, and I did a 50% w/c. A week later, the fish were fine. No cottonmouth.
This has happened to me before with a driftwood piece that I bought at another lfs. Many of my fish died, and I didn't know the rotten driftwood was causing it. It looked fine from the outside, but the inside was another story.
Recently, I owned another piece of driftwood that never gave me any grief. You best believe I inspected it throroughly before I placed it in my tank.
Just be careful, inspect the wood and monitor it if you decide to buy it.