Online real estate site Redfin, once a high-profile showcase for Microsoft's Virtual Earth technology, said this morning that it's switching exclusively to Google Maps in an effort to improve map-rendering speed on its site.

Redfin was using both. Michael Young, chief technology officer at Seattle-based Redfin, says good things about Virtual Earth in the post announcing the change -- calling it a solid choice and noting that Redfin will miss the unique "Bird's Eye" views offered by the Microsoft mapping service.

However, Young explains that Redfin has figured out a way to render pushpins on Google Maps much more quickly.

"In the end, it was speed, speed, speed that convinced us to switch. In our worst case scenario of 500 pushpins on the map in IE6, GMaps is 385% faster," Young writes. " 'Every millisecond counts is a 'Googley' UX design principle that we strongly believe in (see here, here, and here). Users who come to Redfin’s site now should see maps load and render just a little bit quicker, which makes us feel a little Googley inside."

Load times have been an issue in the past on the Redfin site. The company went through an extensive analysis when it originally chose Virtual Earth over Google Maps two years ago.

I've asked Microsoft for comment on the technical issues raised in today's Redfin post, and I'll update this post depending on the response.