I use an Optimus V on VM just like you. Instead of cancelling my expired contract I decided to renew and get the Sidekick 4G. I just couldn't do all-touch typing. I thought I try to get used to it but couldn't. So the keyboard won me over.
It's not a high-end G2X. No flash for camera. Despite the 1ghz processor, it does lag at times when switching orientation. It seems the home launcher uses a lot of CPU because it lags mainly on it. But it is a nice phone. Dual cameras, autofocus. Pretty unique custom UI. You can even change fonts without root.
If it weren't for the need of a physical keyboard I would have definitely stayed with the Optimus V. So if you have one and are considering the Sidekick, I would only suggest it for the keyboard and nothing more.