Wands are ok if a Wizard has a really high Dex. But, high Dex Wizards tend to be weak in Fort and Will saves. Even for a Wizard with a 16 Dex, 85% of any encounter a wand is used, the results for a single attack roll are the same (shy of rerolls). That means that the Wand helps 1 combat in 6 more or less for that Wizard. Even when his Dex is up to 26, nearly half of encounters, the Wand doesn't help at all (since the roll hits without the bonus).
Either use of an Orb can help more than that in more combats than that. They just flat out have more utility than a Wand because they are used after a successful roll, not before.