jayemm,
My personal take on it is that handling a 10kt change in headwind can be a tricky business. Having a 25kt headwind and then having a 15kts headwind is effectively windshere. You only have to read the AAIB reports to see plenty of accouts of wind drops and leaving the runway at an angle with the closing sentence "The pilot believes the cause was windshere". May not be so much of an issue for a C152, but I probably would not risk our AA5A in those conditions.
Another thing to remember is that the wind may well be down the runway, but may not stay like that. A quick look at the synoptics should give you an indication what kind of wind direction change and speed to expect later in the day.
FWIW, I believe that some operators stipulate that the commander add half the gust speed to the wind speed and determine the cross wind component from that.
Something that GASCO and the CAA keep reinforcing and something that I personally have so far taken heed of is, that just becasue you didn't have a problem last time...
Just my personal view that may change with experience.