Not a fan of term limits. What's worst of all are those who want a limit of six years for the House. Who'd be speaker? Someone inexperienced and incompetent? I actually think Ryan is pretty good as a Congressional leader.
Edit: Yes, he said only 6 years for House.
Why does that argument apply to Congress but not the Presidency? The latter is significantly more complex and difficult of a job, but after 2 full terms, the 22nd Amendment requires the President to step down and be replaced by someone who has never done the job.
The idea, though, is that the President has already gotten experience from being in Congress or in a Cabinet. Speakership likewise. You don't want a President to have to spend his first four years learning how to do his job, whereas a Representative has 1) less to figure out and 2) more leeway to do so. Plus, a Congressman probably has already had local experience anyway.