Swap file helps even on systems with higher RAM. My quad core 1gb ram 7 inch tablet gets a major multi-tasking boost from chucking in a 2gb swap, on the uhs-1 micro sd card. And of course, the price of memory goes down rapidly, and even at constant write, nand flash is supposed to last years.
Im basically of the opinion, because the performance difference is so radical, that probably anyone with less than a really large amount of RAM should be doing this. In fact it should probably come as a standard option in android (along with bigger app caches, and a proper sized internet cache).
I mean you have a 64-128gb micro sd (uhs-1), or even the uhs-2 that came out this year, plus a 16-64gb internal nand, often "fast" nand, which is a kind of primitive ssd or even SSD, as are used on windows slates - your not exactly filling all that high speed space up with much. The speed only really comes into play with video, or loading apps into memory - which is exactly the use here.
Of course ideally, manufacturers would focus more on RAM, than resolution or extra cores, because clearly the system speed benefits a lot from higher ram - and they should probably also up the speed of the internal storage too (like switching to full ssd type systems, or at minimum "fast" nand. But in the mean time, while high resolutions tend to cause a sort of RAM deficit in all devices, a swap file, and caching to a reasonably snappy external sd makes a lot of sense.
Indeed it would be nice to see some browsers keep fuller caching too, most browsers are either slow, or low feature, rarely fast and full featured - and thats partly because the space for the app cache on the internal drive is tiny. They are designed to operate within a low memory and storage environment, and that whole story is changing. Even if the ram isn't up to chop as much as it should be, the storage certainly is, and it can be pretty darn fast on UHS-1 standards (or the uhs-2 released this year), even if its not "fast" or ssd.
And the cost of external memory, is peanuts really, even for higher capacity uhs-1. At least a 64gb uhs-1 is perfectly affordable (50 bucks where I am, but it would be less USD), much cheaper than the device, and 32 gb and under is basically a couple of tenners.
Plenty of lessons to be learned from the desktop really, especially now the specs are getting higher - the slowest performance link is loading from storage to ram. The more you can do to mitigate that, the better.