Ruby's carbon, Dolce is aluminum. The frame alone on the Ruby is an upgrade from what you have. If you're reasonably flexible, I'd go for the Ruby. The component packages are what determine the price. IMHO, go for at least Shimano 105/SRAM Apex on a carbon frame. If you can swing it, that'll be a pretty nice ride.

The Elite models are the higher-end. Comp is pretty basic, though the component specs change from year to year.