It is possible by a bit of fiddling about to minimise the influence of BT/Yahoo so I would say go for it. I've had BT broadband for more than two years now and have no complaints until the alliance came up but, I've found I can ignore that!!<-))
Also have had BT broadband for some time and quickly ditched the alcatel usb modem and fitted an internal ADSL pci card. I ignored all bt software, just loading adsl drivers and entered my username and password, and it works a treat.
Just out of interest, would a usb2 ADSL modem perform better than an internal pci card?