I mean the version of touchpad on the system, not kexts version.
For example:
E6420 and E6430 has v3 touchpad
E7440 has v5 touchpad
E7450 has v7 touchpad
E7470 has v8 touchpad
The kext supports v3 and v5 quite smoothly, and somewhat supports v7 and v8, just not smoothly.
With the kexts install, run this in terminal to determine what version you have. I'm pretty sure E7270 is the same as the E7470.
log show | grep ALPS