I guess it depends on who you ask
Really, though I do have a question about SSD and size. It has been asked over and over but I have not seen any threads that really answer my question.
What size SSD would be the best option for me? I do your normal computer operation but do a lot of serious video work. I have many programs that I need to use for different things that I do. Several different things for video(large programs) office, programs that I have for home automation, hundreds of gb of music, hundreds of pictures, tb of video. Large programs for pictures. I know I won't store any of the music, pics or video on the SSD.
I have read many, many, many conflicting reports on what to do with your SSD. My big question is will I get faster video rendering if the program is on the OS drive? Where is the best place to put my programs. On another drive or on the same partition as the OS? I want what will be best for video work.
Remember that SSDs mostly use MLC (Multi-Level Cell) chips which have a fairly limited number of write cycles per cell before they fail - typically about 10,000 cycles. The controllers of modern SSDs will wear-level the writes, so that when it is going to write to an already written sector, it will write to one less used and map that into the logical location where the old version was. This gives better longevity to the devices, but they will "wear out" after some time, depending upon how much writing is going on. These are factors to keep in mind.
All that said, for the most part, using an SSD will considerably speed up performance of your system, especially when doing a lot of disc access. Read operations will blaze, and writes will be much better as well. As for size (bigger is better), the bigger the device, if you do not go much above 50% utilization (most of your data will be read-mostly), then it should last pretty well as that will enable the system to balance the wear on the rest of the drive pretty well.
As rubberman said, using an SSD will increase the performance of your system. In my opinion, you should keep your OS alongside your most utilised programs on your SSD. I don't know how much you want to spend on an SSD, but I would go for this one
I hope this helps.