BGP done right requires a full duplex connection to be up. So this is ok.
[] Point default to NSP #1
[] Take internal routes from NSP #2
[] Have a second, lower pref default to NSP #2
Recently, we have been bitten by failures on our 10mbit link to NSP #1
(default) where the ethernet-lookalike link between us became
uni-directional (common netedges failure mode). This failure was not
Of couse it won't help you if your provider can't correctly send a
default only when he has a proper default.