Of the routers I've tried on my line I get the best speeds (up and down) with either the VMG8924-B10A or a HG635 (the original TalkTalk Super Router).
The Homehub 5B loses me a couple of Mbs download, with the HG612 losing a little bit more than that.
I've also tried a Technicolor TG589VAC which equalled the VMG8924 for speed but wanted to re-sync every day or so, so I got rid of it.
It really seems to be the case of finding what your particular line likes the best.