Insertion Loss: RP-SMA + Antenna versus U.FL + Pigtail + Antenna

So far I have been using XBee PRO S2B model XBP24BZ7SIT-004 with integrated RP-SMA connector but I realized it lacks mechanical flexibility. I am considering now changing it to the U.FL connector XBee version but I don’t have a clear idea about how it is going to affect the performance of my product. If the U.FL version is used there will be a 4" pigtail cable with a U.FL connector in one end and a RP-SMA connector in the other, wich is then attached to an external antenna. Manufacturers of this kind of cable claim it has less than 1dB insertion loss. Considering insertion loss is given by 10*log10(PT/PR) then in the worst case I will be loosing 20.57% of the original power in the pigtail only, right? Does it mean 20.57% less range too? Is there anything else to consider when switching from “RP-SMA + ANTENNA” to “U.FL + PIGTAIL + ANTENNA”?