All smooth runnings . .

So far so good – all functions tested to date perform 100%.
Chose this to replace legacy (and possible security risk?) plugin [Search Everything] which conflicted with [SchedulePress], and [Relevanssi] which, while very comprehensive, would not deliver highlight color for found word/phrase no matter what we tried.

Realistically, if working on a client’s sites, ($$) there is just no leeway to clock up hours and hours coaxing some plugin or other to work.
If it doesn’t work pretty much ‘straight out of the box‘ after configuring, it’s not commercially viable, free or not.
Ivory Search does the job with minimum fuss.

Another aspect: If plugins are a bit finnicky from the get-go, one can wonder about security and possibly heavy traffic performance issues.
Finally: It might seem logical that paying a fair price for a premium plugin would mean first class performance and good support. However, this can’t be taken for granted with some of the outfits that aggregate and sell plugins. Scour feedback on the boards before buying.
Some authors of free plugins deliver excellent products – and deserve a generous donation so they can put a good meal on the table.