They accomplish the same thing, but the probe itself is very different.

Taken from a helpful reddit post: *The BLtouch is based on an hall-effect sensor, while the CRtouch has an optical switch. The BLtouch has a plastic and pointy pin, while the CR has a bulkier metal pin.

The CRtouch is slightly more precise than the BLtouch with a lower deviation delta. They both are more sensitive than the minimum stepping distance of 0.025mm that is found most frequently.

The BLtouch is at its fourth (3+1) iteration, while the CRtouch has been released relatively recently. There’s a lot of information on the BLtouch available on Antclab’s website, while there’s pretty much none for the CR.

I would go for the BL for two reasons: the smaller footprint of the probe behaves better on textured surfaces, and beacuse hall-effect sensors aren’t subject to drifting when aging (unlike the optical switch in the CR, that technically “wears out” and starts introducing an offset to the measurements).*