Up until recently a good replacement drive for a MacBook Pro was typically of a 750 Gb capacity with a 7200RPM spin rate making for a noticeable speed bump. In other words a better choice than Apple’s offerings even on a new machine.
And sometimes discerning owners would request the upgrade at purchase time.
The other option for awhile has been a Solid State Drive [SSD], but these are still pricey, especially if a user needs lots of storage space, but they’re certainly the fastest game in town, despite needing more free space at all times over a traditional drive so they can “scavenge” files and portions of, to keep themselves in an optimal state.
And yes, they need a backup strategy, maybe even more so than traditional drives, which often give some warning signs before failure.
But now there is a good option falling between the two styles, the so called third generation 2.5 inch hybrid drive that combine a hard disk with flash memory…
…8 Gb SSD embedded in standard 1 Tb Winchester hard disk technology. Ideal for productivity software as the SSHD learns the commonly used files and places them in what is effectively a 8 Gb SSD on the drive. This is certainly perkier than a 750 Gb high RPM drives used for replacements up until mid winter 2013. Lesser benefits if doing large video files.