Well,
Looking at the spec's on both, is seems the 380 is basically the same as the 575 apart from DVD-A and SACD playback.
Both have PAL/NTSC prog-scan, the same spec D/A converters etc.
I personally have the 575 as I am getting into SACD in surround sound and find the 575 EXCELLENT for this. Movie sound and picture is GREAT aswell.
As far as I can see, if DVD-A and SACD replay is not important to you, go for the 380. Just make sure you get a multiregion enabled one and not a R2 only machine. (the 575 from Richersounds IS multi region enabled).
TTFN,
Graham.