The Tiny13A gets all the attention, deservedly so, but I'm liking the Tivo532 Z8 setup so far. It's really nice to be able to reprogram on-the-fly by just plugging in the connector to the exposed back of the driver. I'm using it in a P60 (L2T) and it's really nice to try different PWM levels, and turn around your source code changes to actually testing in a light in seconds. First couple of times you try it, think anyone will be amazed when coming from the Tiny13A environment. The Z8 has 8K bytes of program space - 8X more than the Tiny13A, so plenty of space to put in all the bells and whistles, not to mention 7135 regulation combined with direct drive mode.
Sorry to go little off topic here, but I'm thinking this Z8 setup may be getting hot soon so don't get too used to AVR Studio and Tiny13A's . I got 4.7A in a P60 on a Pana PF (over 1,300 lumens), in turbo mode, then Hi mode at a regulated 1.5A, and a nice low, then moonlight level -- nice...