sIFR or FLIR?

I've recently bumped into facelift, an alternative to sIFR and I was wondering if those who have experience with both sIFR and FLIR could shed some light on their experience with FLIR.

For those of you who've not yet read about how FLIR does it, FLIR works by taking the text from targeted elements using JavaScript to then make calls to a PHP app that uses PHP's GD to render and return transparent PNG images that get placed as background for the said element, where the overflow is then set to hidden and padding is applied equal to the elements dimensions to effectively push the text out of view.

This is what I've figured so far:

• The good

  • No flash (+for mobiles)
  • FLIR won't break the layout
  • Images range from some 1KB (say one h3 sentence) to 8KB (very very large headline)
  • Good documentation
  • Easy to implement
  • Customizable selectors
  • Support for jQuery/prototype/scriptaculous/mooTools
  • FLIR has implemented cache
  • Browsers cache the images themselves!

• The bad

  • Text can't be selected
  • Requests are processed from all sources (you need to restrict FLIR yourself to process requests from your domain only)

My main concerns are about how well does it scale, that is, how expensive is it to work with the GD library on a shared host, does anyone have experience with it?; second, what love do search engines garner for sIFR or FLIR implementations knowing that a) text isn't explicitly hidden b) renders only on a JavaScript engine.

Over the long term, sIFR should cache better because rendering is done on the client side, from one single Flash movie. Flash text acts more like browser text than an image, and it's easy to style the text within Flash (different colors, font weights, links, etc). You may also prefer the quality of text rendered in Flash, versus that rendered by the server side image library. Another advantage is that you don't need any server side code.

Google has stated that sIFR is OK, since it's replacing HTML text by the same text, but rendered differently. I'd say the same holds true for FLIR.