My Peterson tuner arrived yesterday and I had a tinker with it last night, comparing against another guitar tuned in standard 440.
Using the "sweetened" function certainly does improve the intonation at certain positions on the neck (Guest, Rigby - I have to disagree with your comment about the guitar being poorly intonated etc, there's plenty of info out there regarding this issue and my guitars are good quality and have recently been professionally set up).
Until I can get together with my other band members and use it alongside the violin and keyboard I won't know how much of an improvement it will offer but, given this device offers a tuning option for using a capo at different neck positions, I'm assuming I'll need to pick a compromise to avoid too much retuning between songs.
What I can say is Peterson do make very good tuners and the strobe display is super-easy to use.
I've a couple of gigs coming up this week and will report back.
C-flat