from my experience there is no difference. I have some .info domains performs very well than other .com domains
Search engines do rank TLD's differently, it is not a myth at all. There has been loads of research carried out on the subject, the most recent of which that I read was by SEOmoz which delves into the topic of exact match domain names. seomoz.org/blog/exact-match-domains-are-far-too-powerful-is-their-time-limited Sorry, I cannot post live links yet as I'm still too new here, but go look at the article. The second graphic is the interesting one, which clearly shows the .com outranking the .net and .org by more than double. Then note the response of the author: Apparently it is surprising to some.
Personally, I found that they are all the same SEO-wise. .com is better however, since it'll get more clicks on google search result and easier to sell/exchange links with other people. This just me of course.