I was using the previous version of this plugin "Advanced WP Query Search".
The first issue is that there was no notification that this plugin was no longer being supported, and the only way I found out was by going to the plugin location...where I discovered the discontinued support and referral to this plugin. All I can say, it's not hard to push out an update with a message regarding discontinuance of support and the move to "Ultimate WP....".
Second, there is no way to save the settings. You got to start all over with the new plugin, from scratch.
Third, had a lot of server timeout issues when setting up the new searches.
Fourth, it gets bogged down and if you have more than 20 taxonomies in a search form, it will only record the additional taxonomies past 20, ONE at a time.
Fifth, it is not playing nicely with my dedicated server, and really slows things down.
Sixth...and this is the death issue, the searches are not accurate. I choose a taxonomy for "Antique Malls" and get stuff from 6-7 other taxonomies. This is with it set at "OR". It
s a bit better if I add some "A'ND" meta fields...but this should not be necessary.
All in all, I wasted two days on this puppy before deleting.