Adj.

efficient; practic; pertinent (Viacheslav Volkov); reasonable (особенно "дельные замечания" Moscowtran); competent; sensible; sound (She gave me some very sound advice. fddhhdot); defendable; defensible; hame; home; practical (of advice, an idea, etc.); decent (Much of the information being presented will be from non-experts, who simply don't have the qualifications to offer decent advice. Abysslooker)

Gruzovik

businesslike; able; capable; judicious; intelligent

Игорь Миг

brainy

kont.

good (that's a good tip Abysslooker)

worthwhile (Andrey Truhachev)