• Complaints about DO shutting down instances and locking accounts until people FAX'd in a copy of their driver's license, passport, etc. (If a user isn't breaking the law or violating the ToS, why does DO need identification? If a user is breaking the law or violating the ToS, then terminate their account!)
• Having to stop accepting signups in their Amsterdam location for a while because they ran out of IPv4 space but didn't support IPv6. (A message from August 2012 says, "we hope to have something in the works by Q4 2012 or Q1 2013." As far as I can tell, they still don't support IPv6 in any of their locations.)
• Not supporting the booting of custom kernels. (They've been stalling on this at least as long as IPv6 support.)
• Botching their Ubuntu image and having everyone's Ubuntu droplets sharing the same ssh host keys unless the user explicitly generated new ones. (Probably an honest mistake, but that's sloppy, especially considering they're effectively forcing users to use their distro images.)
The recent kerfluffle about not always wiping data after a user's disk image is destroyed would've also been a gigantic red flag (that had been doused in kerosene and lit on fire before being run up the flagpole) if it had happened a few months earlier.
To be fair, Linode's security/privacy record is far from spotless — they've been super evasive about breaches, and their handling of a data leak bug/vuln I reported didn't leave me with a super-awesome feeling — but my gut feeling is that Linode sucks just enough less to justify the US$15/month extra. That could easily change, though, but I imagine it would turn into "both suck, screw it, I'll suffer with an EC2 t1.micro instance."