40X scary? No, just check your helmet and tighten your seatbelt ;-)
A friend asked for assistance designing a prototype semi-autonomous locating/tracking device. My design used a 40X2, a 28X2, and a uM-FPU (managing a GPS and about a dozen other peripheral devices). The person funding the project has decided that I2C between chips is too complicated (i.e., he doesn't understand it) and that a 32 bit ARM chip (probably in the Cortex series) would be a better choice (the ARM chip includes a vector FPU). Many of the peripherals are I2C, so the need to understand it will still be there. I don't think he's discovered how much configuration is required to get the pins on one of these chips to perform the functions needed - what the PICAXE does with the SFRs behind the scenes must be done by the programmer (READTEMP is a marvelous simplification of the one wire process). If the potential market were in the tens of thousands, I would say the economics made sense (~$5 for one chip versus $40 for 3 chips), but for potentially a few hundred units, the cost of the switch to C/C++ development will likely exceed any savings on the chip/board cost because it will take several months to translate existing functional code to the new platform.
Oh well. I did get to play with a multi-PICAXE breadboard and some cutting edge toys as I assembled the prototype and tested the interfaces to the "goodies": 3-axis accelerometer, servo mounted laser, FRAM, I2C digital compass, I2C thermometer, etc.
John