Modern Sterns are really tough to beat... why not take aim at your T2 or TOM and take those to task?
I'm not a superstar by any stretch, but I do know you'll advance your game skills by flipping less and focusing on controlling the ball. Play one handed and you'll start to see the value in dead flips and trapping up. At least that's how I've managed to get better.
Also, learn how to nudge when the ball gets around those outlanes! This might seem counter-intuitive, but I like to keep my tilt bobs sensitive... that has really helped me to hone nudging skills.
The idea is to slow the game down (and not by tightening up the outlanes and lowering the pitch of the playfield). It's done by anticipating, reducing the amount of chaos, and manipulating the machine to advantage you and not the game design.
Don't give up. Just take what you've been doing and do it differently!