I tried it, I bought it.

Basically, this is lightning fast image combination. The results are nice, though they are only 8-bit JPEG, so it does not create true HDR images. Nonetheless, the results are impressive, and the matching algorithm is significantly better than competitors.
There is nowhere near the level of sophistication of the photomatix software, but, on the other hand, it runs about 60x faster (no, seriously).
If you're a serious photographer, and you only intend to own one kind of image combination software for HDR, then don't buy this one. Buy Photomatix instead.
On the other hand, if you're happy to own more than one tool for more than one kind of job, then this is superb for what it does.
And, if you're the kind of person that still uses iPhoto, you'll find this an absolute joy to use.