It really is anoyying, I remeber. I hated that when I had the Apache. The only thing that really lagged it though was when WiFi was on. However, using
Wakeup Tweak and setting it to wake up to full power fixed it. Only that the phone will wake up on it's own sometimes for no reason. If you use
Slide2Unlock you can set it to turn off after like 5 seconds of idle when the screen is locked. Worked for me...