Have Both,
i5-2500k - 128 gig Samsung 830 for OS + programs and an 120 gig Agility III for storage/work drive.
Samsung RF711 laptop - a pair of 128 gig Curcual M4s.
Performance wise, maybe a nickels worth of difference in real life day-to day work.
If nearly the same price, recommend the Samsung 830 as slightly higher realiability. If more than 10% cost difference - get the lower priced one.
@ "If the machine you're using doesn't have SATAIII ports, you're only going to get half the read/write speed but it will still be a great drive."
For an SSD used as a OS + Program drive, - Not true in real life, day-to-day usage, only in benchmarks and then ONLY in the least important matric for an OS + Program drive, Sequenial read/writes. Only a small performance gain for the more important 4 K random performance. Overall real life performance diff for an OS + Program time is more like 15->20 %. Must remember that ONLY the OS Load time is improved, program load times, and files that are on the SSD are affected. For OS and programs most of these files tend to be small files and SATA III does not saturate a sata II interface for the 4k random.
Infact the Agillity III performs NO better on sata III as opposed to being installed onSata II. This is a poor example, as I hate to use Agillity III in the same sentence as Sata III.