As a data recording technology for hard drives, PMR is already 10 years old. So far, SMR is not a suitable replacement for PMR; hopefully, HAMR will be. Interestingly, SMR seems like the true MR technology that begs to be a hybrid. Considering data is written in bands or blocks like an SSD (SMR also implements TRIM), I can see SMR hybrids producing the performance we expect from a HDD without the SMR write performance pitfall. With hard drive manufactures having better access to NAND flash (e.g. WD buying SanDisk), hopefully we'll see more hybrid implementations that give us better HDD performance (certainly it won't be SSD speeds) with the ever-increasing capacity we expect from spinning MR technology.