have you been to Mexico? did you take us$ or did you buy Mexican money in the UK and take that , i have been told that the us $ is best but then another person said Mexican was best, i know it is Mexico so you would expect to take Mexican money but in my experience that is not always the case. thanks in advance for any info,
In Mexico city there was no point offering other than pesos.
In a small resort on the Pacific coast, ditto, though a few places would accept USD.
In and around Cancun, totally infested with Americans, the Mexicans naturally assume that the US citizens will have only brough USD and everything is dual-priced - at not particularly favourable rates, as I recall. This was 3 years ago.
I'd take pesos - this is not the Zimbabwean dollar, you know.