Nope, it will be different for every phone/user. You have to test till you get what's best for you.

 

What he said.

 

The lower the voltage, the better the battery life. The higher the frequency, the higher the performance.

It's up to you to find the combination that works best for your phone / style of use.

 

I found a REALLY nice setting @ 1.35 with 72vsel. Works GREAT, fast and quick and still get more than a whole day on my extended battery.
My settings are:
1.35 - 72
1.1 - 64
0.9 - 58
0.4 - 38

 

I use 1.25 ulv. I have literally no lag and the phone is very snappy despite having a stock 2.2 blur home. Not even using lp. And I have never seen this kind of battery life improvement with anything I've done on my phones since I picked one up on launch day. I browse the web a good bit and yesterday I was at 60% after 15 hours unplugged.