Code-only DGPS/WAAS - What's the point?

I was just wondering how and where these pseudorange (without carrier
phase) corrections could be sensibly used now.

Ok, we have a slightly better RMS using that in _ideal_ conditions.
But in urban-like environments things like multipath and high PDOP due
to low number of usable satellites can cause errors up to 20-30
meters, and those errors obviously cannot be canceled by pure-code
DGPS/WAAS.
As a matter of fact we don't have to go downtown to have multipath at
the level of 3-5 meters, it's not uncommon, and even that makes pure-
code corrections practically useless.

What do you think? :)