Opinions on rankings for "not-com" TLDs

Title says it all. What are your experiences and opinions on TLDs that are not ".com", assuming the extension fits your site/niche and sounds good (for example ****** spells adfly, etc). Do these get bad ranks from google, do they get better ranks? Just need a little more info before pulling the trigger on buying a domain for a niche that honestly doesn't have the competition you would expect.