As relevant if not more so here in 2015, anyone using any kind of Mac without an SSD should look at upgrade options that really boost performance. From 2013:
Here in 2015, SSD prices have declined very nicely vs 2013. The OWC Electra 6G series is wallet friendly at just $132 for 240GB, or $235 for a 480GB SSD. The OWC Extreme Pro series offers a bit more performance, but the night and day difference comes from upgrading the hard drive to an SSD.
Note that old-style laptops and MacMini models can accept dual internal drives (SSD or hard drive) via the OWC Data Doubler. If the goal is storage capacity, current model 2.5-inch hard drives offer up to 2TB capacity.
With Apple removing TRIM support in the latest OS X versions, the drives recommended above do not need TRIM and never have, which in part is why MPG has been recommending them for years.
MPG likes “set and forget” products which just keep working reliably—some SSDs will slow down as they fill up and become internally fragmented, and this may be not only a speed issue, but a NAND (flash memory) wear issue (longevity).