I use them sometimes.. No noticeable problems or bad effects.. I think people just don't like typing info
It's more of a concern for branding. .info looks too spammy still, and it's not widely accepted as an authoritative site (there are exceptions, of course).
dot info are fine for SEO, it's really only branding that they are still frowned upon for. One of the infos in my sig ranks 2nd on Google for the main keyword so no problem there with SERPs.
The only problem with .info is that they were used for scrapers and spamming a lot some time back. So branding them will be a problem. But they have no problems with SE's