I never roll for the players either. They have their PCs and have invested a lot of time into them, I don't like to make them feel as if the GM is taking control away from the players.
While that approach may make it seem like the players know the outcome based on their rolls i.e.: OE up or down, there are ways around it. Just because a player has open ended high, it does not equate to success. It simply mean they rolled high, did an excellent <insert task here>, but the opposing person could have rolled higher, or simply set a trap that was above their skill level. For example, Detect Traps yields a roll of 136. The trap maker rolled a 183 for setting/making the trap. Great roll on the PC's part, just not as good as their foe. That helps set the mood for the party too. They all see the open end, hear the 136 and applaud, then discover it wasn't enough as the trap goes off. The party starts to wonder "Oh crap, who are we going against???"
If the player OE down, it does not always mean instant fail. I'll use this sometimes if it's a dumb luck roll. Ever do a Where's Waldo and the very instant you open the page, you're looking right at Waldo? Purely accidental, just dumb luck. I'll use that OE down roll when It's simply way above the skill level of the players and only dumb luck can help them, only by stumbling right into it, can they succeed. It keeps the players still excited about rolls, even if they seem like failures.
Ever walk barefoot on the pool deck and you find the only nail sticking up? You weren't looking for that nail, but damn it, you found it!
Sometimes, to keep the players on their toes, I'll roll the dice, do some fake math in my head and say "Uh. OK. Keep going." That really messes with them