Their chips are fine and their JTAG system is something special. EC2 JTAG is cheap and does not disturb chips in operation. Newer USB JTAG is even cheaper. Personally, I am using the smallest ones (F304), MCU with USB (F320) and the fastest one (F122) and the only problem is a price. If I need something for experiments or low volume production, it is my first choice. But for the future "hgh" volume modular system I am evaluating HCS08.
Last but not least, I am using Silabs IDE instead of Keil's uVision 2 one, because it seems to me to be more stable and faster when downloading and debuging.
Jan