Considering my bandwidth is not trottled at all (I can download full bandwidth with p2p at any time), this is definitely a SE issue.
I live in Italy and my provider is MC-Link, and I definitely have the same issues which started around monday: 2-3 seconds lag spikes every 10 seconds, more or less. Considering I never had such a problem, is something recent.
Oh obviously it's not and FPS issue because I can move while lagging.