definitely subtle. it seems that Lord-Alge's mixes are a bit "wider" than the originals. HTB also features Matt (asking Dave, probably) "were you smoking lots of grass when you did that?" during the pedal-distortion "solo."
Strange Days has that vocal echo and it seems like there's a bit more crispness or something coming from the acoustic in the background. i'm not too fond of the remix either.
Everything is Automatic has some noticeably different guitar sounds, which you can pick out during the chorus. it basically sounds like they were placed higher in the mix. the drums sound a little "rounder" too, like they're given an echo. and of course Matt's vocal is overdubbed here and there differently and with more echo. basically, more guitar and echo.
all in all, i think the remixes are basically "wider" sounding versions of the songs with louder guitar sounds. probably an attempt to make the singles (and prospective singles) sound more "mainstream." i'm quite satisfied with the old mixes and i don't think remixing these songs was necessary. then again, what the label wants the label gets.