Re: '88 band.
I thought it was very much a mixed bag. The new songs (mostly on BTHW) were very well done. The old songs however, were rather hit or miss. Quite a few got a pretty good shot in the arm from the big band treatment, especially the instrumentals, but the downsides:
1. No Ray White. Ray was my favorite vocalist from the 80's trio (w/ Ike and Bobby), and the songs which Ray White had adopted in the early 80's, such as "City of Tiny Lites", "Advance Romance" and "Zomby Woof" just don't sound right without him, and whoever they had singing the songs instead (Keneally?) doesn't do them justice.
2. Too many covers. While it was interesting to hear Zappa's take on some notable 60s/70s songs, I didn't think they were all that great, and they could have been cut for other classic songs from Zappa's own collection (ex: Packard Goose)
3. Zappa had shifted from the subtler satire of, say, Joe's Garage and shifted to a more direct approach at this point, namely all the anti-Reagan songs (though to be fair he did lampoon Jesse Jackson as well), which, while good, also shows the date/age of the material.
4. "Stevie's Spanking" without Stevie? Come on...
5. Due to age and possibly the onset of disease which would kill him, Frank's guitar skills had diminished by this point, and it shows on some of the tracks. Another notable example of this was Frank not being able to pick out a good solo for "Black Napkins" on MAJNH.