Even 1Gb/s LAN (100MB/s) has troubles competing with modern 2.5" internal drives.
WiFi is a lot slower than that LAN.
If you only request small files in a random manner the Wifi SSD might still win but I really cannot imagine any usage where this might be the case and worth the money.
I was thinking of putting some SSD's on a network, to be used wireless by my notebook(s), but after this thread, it would seem pointless to do, as there would be no performance gain.
You can easily answer this yourself with some quick Google searches. Best case with 802.11n is 600Mb/s or 75MB/s (8b = 1B). Consider that SATA 1.0 drives have a limit of 1.5Gb/s, or 150MB/s.
Yeah, that is where I get lost. There is the theoretical output, and then real world output, of which I can't tell which is which, nor do I know how to calculate it.