Now that I don't have the ALDA, the speed is just the same as it was before...

Still just as slow as it was before, just missing a part. Do I still need those fancy guages?

If you value your engine, yes.

I've removed the ALDA's from the 603's. I don't have any boost gauges. I'm not worried about it.

Most of the overboost systems don't work anyway due to plugged sensors. You can have a proper ALDA, a proper overboost solenoid, and still overboost the engine if the wastegate fails.

Not if the system works correctly, most do.