I've noticed on the train these work very well. They isolate alot more than my last pair of canal phones and thoes worked ok on the train. We have had some below 0 celcius weather lately and these cables have stayed suprisingly flexible. They don't become stiff and pull at your ears like a few of my other pairs...still quite happy with these phones!
I had to laugh today, after work a friend took out her ipod with ibuds the same time i toko out my ipod +c700's. I hold them close to the plug, let them fall and all of a sudden the knots and tangles are gone, then put them on. Meanwhile i took at hers and it looked like someone purposely tied about 20 knots in the ibuds. I left and she was still undoing knots, lol.
Edit: Sony tips should fit, i'll try the sony silicone tips with these tomorrow and report back my findings if they work well.