Check out the Nitro to see if you like the build quality because it should be fairly similar to the Spectrum. The Nitro has a great screen, IMO. I like it better than the Rezound and Gnex. So if the spectrum has the same screen I think it beats the rezound.
One difference that I have seen between the Nitro/Rezound vs the Spectrum is the processor type. Same speed but the Spectrum uses a newer SnapDragon chip set. This should help reduce heat and power consumption.
So far, the spectrum has a bigger and better screen, an up to date processor and a bigger stock battery than the rezound. So it's going to be a tough choice with the Rezound's price dropping, HTC unlocking the bootloader and I believe HTC uses the best cameras on mobile phones. Also, HTC seems to have a better track record in the smartphone making biz than LG.
I can't wait to see the reviews on this phone.