Depends, fiberglass and mineral wool, blown in, as yours is, or batt loses R-value if compressed more than slightly. Cellulose, typically gray shredded paper, handles a fair amount of compression while maintaining R-value. It is tolerant of compression to the extent that I'm not sure you could reduce the R-value much pressing on it with your hands.

Also, to avoid confusion you might need to know that R-value is simply the inverse of U-value. U is the older term. A R-value of 2 would equal a U of 0,5. R replaced the older U because it was thought that people would be more comfortable working on the larger side of the decimal point.