I've not tried Karma+Jammer+SSLStrip (interesting combination), but over the long weekend I spent time working on Karma and SSLStrip. I saw what everyone is saying about Karma - not all that successful against modern devices (ironically, I hooked my iPad with Karma).
SSLStrip was much more successful. WRT Facebook, I was able to strip m.facebook.com; in fact, I succeeded against most mobile interfaces to social media. I was somewhat disheartened by how many sites SSLStrip actually worked with! So I'd say keep trying. HSTS is apparently not widely used yet.
It might be time for me to try my own infusion, which redirects from www.*.com to m.*.com...