Today Apple announced relatively straightforward storage capacity upgrades for both of the “multi-touch” iDevices, doubling the standard versions of each to 16GB and 32GB for the iPhone and iPod Touch, respectively.

Other than the storage space upgrades, according to reliable sources in Cupertino, the new iDevices use a somewhat different type of Flash storage that should offer substantial transfer performance improvements (especially for large files, since part of the difference is better buffering and sustained stream optimizations, as well as some improvements in the loading of large numbers of small {1024K or less} files — such as in a Web browser’s cache).

Overall, the iPod Touch should see between 50 and 300% depending on the size of the file, and an average of about 75-125% faster when syncing typical-sized MP3/AAC songs to the iPod.

The 16GB iPhone uses a somewhat smaller, lower-power/operating-temperature version of the same storage module and on average gets about 80% faster performance during a typical iTunes sync filling half the storage module (8GB) compared against the complete filling (also 8GB) of an existing model.

Interestingly, the max burstable performance of both devices is about the same (around 300-333% faster than current 8/16GB modules in existing iDevices), since they share similar buffer units and similar optimization routines for “write-behind” and “read-ahead” prediction.

Pricing hasn’t dropped as yet, however — the 8GB iPhone is still $399 new, $349 refurb.

Refurbished models will probably drop to $299 soon, and price drops for the new iDevices aren’t terribly far off; but for now, the $499 16GB iPhone is looking like a great buy for those who have been waiting for more/faster storage. You won’t be disappointed.