Christopher Semturs, the Googler who is the man behind geo-specific search engine visibility topics, posted a thread at Google+ asking for feedback on the use of the hreflang attribute.

He wants to hear from SEOs and webmasters who have implemented the hreflang attribute to see if they got out of it what they expected.

Christopher asked:

So this is your chance to speak up and have a Googler review this specific attribute with you to make sure Google knows what you want out of it.

So far there are almost 40 comments on the thread but they want more.

Past articles on this topic include:

Google On hreflang Attribute, Sitemaps & Geo Topics
Google Improves Multilingual Support With Markup

Forum discussion at Google+.