While the unit is capable of allowing a Roland-ready guitar in standard tuning to play in alternate tunings (such as Open-E or Keith Richards' favorite tuning, Open-G), these VG-88 created tuning conversions sound far better playing chords than single notes and arpeggios. There's a microscopic but still noticeable glitch or overtone when the VG-88 transposes a note into anything other than octave, for example, when the unit has adjusted the E string down to D, in Open-G tuning.
Still, if I was playing live, and my band had to do one song in open tuning (Say "Start Me Up" or "Brown Sugar"), this could be a viable alternative to carrying a second axe or retuning between numbers and slowing the pacing down. And speaking of which, there also some very usable bass patches, which would benefit the guitarist who needs to play bass from time to time live, but doesn't want to schlep a Fender bass to the gig.
The VG-8/VG-88 wiki site has a wish list of features for Roland's next generation guitar modeling product; I would like to see the ability to easily raise and lower the output an octave by pressing a foot pedal, particularly with the synth and keyboard patches. And an effects loop for additional, outside stomp-box effects would have been nice. Also, a pair of low impedance XLR outputs, and a digital and/or USB audio output would have been useful as well, though the combination of left and right quarter-inch outputs and a separate quarter-inch stereo out are certainly serviceable. Also the unit should come with USB-enabled patch editor software, and not rely on third party MIDI software to do the job.
But those are all relatively minor quibbles compared with what the VG-88 is capable of, and what it portends for the future of the electric guitar. That "Guitar Army" that Jimmy Page was always talking about in the 1970s? Its footlocker is here.