Simple or not
Concur. Of the two, choose the SSD over increased RAM, if for no other reason than the RAM easier to upgrade in future.
Anecdotal reports have the MacBook Air seemingly quicker and more seamless than the MacBook Pro. This likely due not only its SSD, but also the integrated design of the architecture from the outset. Thus installing an SSD in a MBP may still leave it at a slight disadvantage
unless demanding tasks are required. For pure horsepower the MBP would remain the best choice. The inclusion of an SSD would negate most advantages of the MBA, and in maximum ability provide the best 13" computer.
The MBA commands a premium for its more svelte form, but it is interesting that the equation can change somewhat depending upon configuration. The price of a new MBA or MBP (2.3 GHz), each with 4GB of RAM, and a 128GB SSD, are nearly the same. But of course the MBA cannot be changed from specs initially configured, while the MBP can, with also a decidedly faster CPU, and more ports.
The MBA can even be a little less expensive than MBP, if bumping up to a 256GB SSD. In just storage alone, there is a good reason to consider that size. Yes, expensive, but using but 128GB is accepting certain hard limitations. The MBA is a sense perhaps cousin to the iPad in purpose being more cloud based. If the MBA quite capable, neither is intended for the really hard work the MBP line better suited for. Which work can often not only entail hard processing, but also large files. In workflow alone, it might really be preferable to retain a good deal internally on the computer.
Assuming use of the MBP, then the possibility of upgrading to an SSD later. There is also the issue of emerging SATA III, that versus SATA II. As RAM, Apple charges a premium for an installed SSD, but also perhaps some reason to pay it. Not all SSDs are created equal, and while some may actually prove better than what Apple offers, some people have experienced various problems with certain after-market types of SSD. If installed from Apple, then one should have no issue taking it back to them if all does not work properly.
Some like tweaking all these parameters, others just want it to work. If you lean towards the latter camp, then messing with RAM later, versus an SSD, would be preferred.
