Rob,

Erik is correct when he says that experience is a hindrance when dealing with the SiLabs "deviates."

However, if their feature sets match your application (which they do, in my case) then don't be afraid of them.

Just carefully RTFDS, which is advised for any chip.

Watch out for odd stuff like JTAG vs C2 interface, shared pins (C2 data and port I/O), resets that can be an input and an output, etc. Some parts have "software interrupts" (set a bit in a register and an interrupt is triggered). Some parts let you use any bit in Port 0 as INT0 and/or INT1. Some parts give you INT0, INT1 and up to four (or eight?) other external interrupts. And the I2C interface control on older parts (like '0xx) differs from that on newer ('3xx) parts. It can be confusing.

And I can guarantee you'll choose a part and then go, "...but this other part has this nifty feature that will make life simple for this specific thing" but that other part won't have another feature you need ...

-a