I don’t know what you would classify as “normal”. The reason I am interested in higher than typical (typical seems to be about 3Hz) sampling rate is because I would like to measure the energy consumed by electronic *equipment* which, yes, may have high frequency fluctuations in power consumption. I agree with you that over a long enough time, it would average out, but I want the flexibility of measuring with a higher sampling rate – and the higher sampling rate will be more useful for shorter tests rather than very long tests, HOWEVER, even in long tests, it would be useful to be able to zoom in on any events of interest. Just FYI, I notice that Adafruit use a power meter from Monsoon that does appear to have a high sampling rate, but it’s about 6 times the price of the Mooshimeter, and seems to be dedicated to low voltage & power equipment. (I’d much rather get something more versatile like the Mooshimeter)
Regarding spreadsheets crashing, well, that’s one reason to consider allowing the meter to do the accumulation, rather than offloading it – if all one is interested in is the final watt-hour reading, it’s a bit of a hassle to have to post process the log. Pretty minor issue though – it’s trivial to write a bit of code if required.
EDIT: There’s no need to try and sell me on the Mooshimeter – I’ve already ordered one, as I said before. :)