SMR disk drives with hybrid E-regions that include a nonvolatile solid state memory E-region in addition to the magnetic media E-regions on disk are described. The memory E-region can be used in operations that will be referred as destaging and/or restaging to sequentialize sets of exception records to reduce the time and energy spent in executing seeks in the disk E-region. The ratio of the size of the solid state memory E-region to the total E-region capacity on the disks can be optimized for selected applications according to the invention using tradeoffs between performance and cost. For example, an embodiment with a memory E-region size that is 10% of the total disk E-region capacity achieves substantial performance enhancement over a disk-only E-region implementation and also results in smaller costs than would be required in a NAND-only memory E-region.