valioso

adj. rewarding; valuable

adj. valuable, costly; valued

= valuable, rewarding, precious.
Ex: Both at the indexing and search stages, as will be seen it is valuable to have relationships between indexing terms displayed.
Ex: Finally, I wish to thank all of the speakers, reactors, and attendees who made these institutes so memorable, exciting, and rewarding.
Ex: Here came every sort of human ingredient -- sturdy homesteaders, skilled craftsmen, precious scoundrels.
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* muy valioso = highly valuable.
* resultar valioso = prove + valuable.
* servicio valioso = yeoman service.