It really depends on the campaign and the adventure.
Some games, a sword that lets you leap 30' is super important; you can't overcome the challenges without having a way to climb/jump/fly up the greased 30' high tube. Other games, a +2 to attack is essential- without it, you can't hit the monster unless you roll a 17+.
Personally, I think they're about even overall for my style of gaming. Then again, that's assuming that the "effect" and the "plus" are roughly equal- the balance is different if you're comparing a sword that gives you +2 to intimidate once per day against a +5 attack and damage and double damage on a crit sword. Likewise, +1 to damage (only) pales in comparison to a sword that lets you summon an iron golem 1/hour.