##RAM upgrade above 8GB if...##
- you do run Virtual Machines excessively because you need to allocate a lot of RAM to the virtual OS
- Other than that, this will most likely not be necessary. Mac OS X operates very efficient with 8GB of RAM. If you do not run VMs, there will be no increase in performance in most cases!
##SSD upgrade if...##
- you want a snappier response throughout the system.
- you run big programs such as Adobe or photo editing software that take long to load.
- you need faster boot/shut down/sleep times.
- if you carry your MBP around a lot. SSDs are very shock resistent. No mechanical parts move.
- if you want a more quiet MBP.
SSDs also consume less power. But you won't notice it significantly.
Think of this: In today's computers, the bottle-neck of processing is usually the hard drive. Processors generally need to wait for the hard drive's read/write operations which are a lot slower. Thus a faster hard drive is needed for a better overall performance in processing. RAM won't help if the needed amount is saturated.