This should be pretty much a given. The key is to strike a balance where (a) you're not touching a pagefile (so disable it, but be aware OSX does not handle running out of memory gracefully - Windows was always much better at this), and (b) you're now purging your file cache so harshly that truly commonly accessed files are read from disk.

It's a dance I've been doing with my MBPs for years now, and I'm sure I'm not the only one.

This 16GB-related conclusion simply supports the performance at a larger workload.

I'm also somewhat ambivalent about the profound benefits of an SSD. For one off tasks, sure, the benefits are obvious. But OS X has a very effective file caching scheme in place. I ran some repeated tests of building large java projects off the HDD vs off a RAMdrive, and, after the first pass, there was no difference in performance.

IMHO the biggest benefit to be had from an SSD is the massive jump in access to random small bits of data, from app launching (phenomenally faster) to index building, cache reading, etc. But I say this as a guess...

Corsair 16GB RAM for under $200 - http://www.corsair.com/pressrelease/corsair-announces-8gb-and-16gb-ddr3-memory-upgrades-for-apple-computers, 120GB SSD just over $200, roughly $400 extra will revive your two years old "ageing" MacBook Pro, this is not bad deal.

Need to find a cheaper, refurbished MBP now ...

http://www.techbuy.com.au/p/181013/MEMORY_NOTEBOOK_DDR3/Corsair/CMSO8GX3M1A1333C9.asp I think it's the same; there is one letter difference in the model ID (O instead of A).

+Kieran Simpson a better deal - http://www.itspot.com.au/corsair-16gb-mac-memory-1333mhz-cl9-ddr3-so-dimm-for-apple-p314980.html

Another Apple helper - http://www.everymac.com/ultimate-mac-lookup/