Eric, Matt,
You are right in that the 'when to use this approach' will be answered by which method is less expensive. The blobs of text in the page should not increase the size of memory or the DOM tree because they are in stored as text. It should also not
impact (too much) the loading of the page because the browser has nothing to parse into DOM. It's not until you turn it into a js object that they are loaded into memory for manipulation.
The instances where I have used this, and similar code, has been when I need data merged from two lists (share a common column). In these cases, it just too long to do it client side. The other was to generate stats (where I would have had to otherwise
pull all the data client side) and in one case to retrieve column data unique values (CAML does not have a select distinct query). It's in these unique cases that I fall back to a DVWP doing the heavy lifting. As I understand it sharepoint also does allot
of smart caching on the server, so it should not increase the response time too much.
Every case is different.
_____
Paul
Sent from mobile device.