After waiting patiently for many months, I finally came across a CyanogenMod port for my LG Vortex. Over at Android Forums, bobZhome has released a CyanogenMod 7 ROM for the Vortex. There are some issues with the 12/2 release (the latest at the time I wrote this) so I recommend following the instructions in this post and installing the 11/9 release along with the listed fixes. There are a couple of things to note about the 11/9 release. First, the screen animations must be disabled in the CyanogenMod settings. Otherwise the unlock screen will be black. Also, you must enable international roaming to get data to work. So far it hasn't caused any extra charges to show up on my bill.
I have been running it for several weeks now and I am very happy with it. I am using the smartass governor, bfq scheduler, and have it overclocked to 768MHz. The kernel can be overclocked to 864MHz but my phone can't handle it. Note that using the GINM kernel requires a 3rd party app to set the governor, scheduler, and clock speed, such as Voltage Control or SetCPU.
Everything is smooth and fast and battery life is great. I have seen a couple of seemingly random reboots, but I suspect overclocking is partly responsible.
So head on over to Android Forums and grab this fantastic ROM. Of course, do a nandroid backup first and don't blame me if you brick your phone.