SO technically just rooting isnt going to show much of a difference? IF you did the overclocked LV and it is finicky such as your phone's experience, how hard is it to back out and start over fresh?
just simply rooting isnt so much about performance, but what it enables you to do from there. A lot of people root just to take advantage of wifi tethering, freeze some programs and run themes/change the status bar.
I look at root as more of a gateway. As for starting over fresh with voodoo its a little more tricky (or at least the potential for it to be more tricky). Because voodoo isnt a "regular" kernel in that it changes stuff in your phone, you have to disable or remove it. You can however flash voodo kernels on top of each other if one gives you a problem. When i tried lv and it was freezing/turtling i booted into clockwork, wiped davlik cache and then installed sv on top.
That being said, and many here have made a great point of saying it, get comfortable and reread all the posts warnings many,many,many times before setting out on voodoo kernels. make sure you have android sdk installed as if you completely bork your phone with voodoo and cant make a disable_lagfix file you ll need the sdk to remove it in recovery.
i know we all seem to greatly advocate going with voodoo, i would never want someone to try something they are not comfortable with. theres always a lot of cheerleading (from me and others) to "do this its great!" but there is the caveat of prepare for the worst, hope for the best.
Be ready to odin, voodoo uninstall, battery pull, 3 button recovery, stare at your computer, throw your keyboard, yell at the phone as if it understands you
and remember the phone unrooted stock may be just fine for you, or simple root maybe too. better to wade in then dive.