I haven't used Tiagra, but the fact they're dual-pivot suggests they should have more than enough stopping power. If you can't make the nastiest pair of dual-pivots in the world throw you over the bars, there's something wrong.

Sh|t and sugar must refer to their feel or something. In my experience, the biggest difference between Exage and 600 dual-pivots is the looks. It's nice to know you have cute little thrust bearings in there, but if they're set up right you can't tell the difference.