Actually, it seems that the very first 2500 released were equipped with the good old sensors like they used to put in 3k, 4k, 2k(XL) ...
but most of the 2k5 have been sold with those s****y sensitronics.
In the same way, the very first black 1ks were still equiped with the s****y single style pads you had in the blue ones.
BTW, Interlink sensors last quite long so if you need to change your sensor sheet you probably have the sensitronics
Something quite common and good to know is that Sensitronics die "row by row"