Saudade

I got a impt project going on which uses a lot of plugins: NI B4/Absynth/smartelectronix stuff, as well as Spectrasonics Trilogy/DFHS Custom&Vintage(rompler), plus some live guitars/basses...

Given that I'm working in Cubase SX and my AMD64 system can tolerate the extra load, would choosing a 88.2/96khz sampler rate for the project settings yield any noticeable improvement in sound quality of these plugins (VSTis and Romplers) over my usual 44.1 setting, during playback AND mixdown? (downsampling to 44.1 will be done in R8brain Pro after mixdown)

In simple terms, does running in hi-def rates make sense when the sounds are "generated" by the plugin software, or are triggered from 44.1khz samples?

I understand this might have something to do with the D/A converters I use to monitor the playback, but would there be a REAL improvement in sound quality discernable in higher end systems (even if my D/A can't reproduce it well)?

What about the case for Gigastudio 3, which can run in 96khz ? (though my giga samples are all 44.1khz)

(the efx plugins I will use to process the VSTis/Romplers will be mainly UAD-1, URS, Sonalksis stuff, convolution verbs with SIR )

Thanks for any info!