P3droid does have 250-1000mHz as well, see here:
P3Droid Kernels
...but you might want to try messing with your advanced settings in SetCPU mine are at 32,000, 93, 0, 0, Set on Boot and I run the P3Droid 125-1000mHz kernel, and it seems to recover from standby pretty quickly. Go to here:
http://www.droidforums.net/forum/hacking-faqs/47871-overclocking-101-a.html
..and see if you can learn how to set your SetCPU to work optimally. Mine used to have issues with coming out of standby lag, but it does not have problems anymore. Some of it has to do with the JIT or something adapting and the phone should get faster with time, but some has to do with other things. But go read that thread and he explains how you can diagnose what is causing the lag. There are tools like System Panel you can use to help figure out what is going on.
I don't even know if my phone has that delay like you describe showing the caller ID (I'll have to pay more attn), but in every other form, the wake-up lag is all gone now.
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