Further to Andrew's comments...
Lightroom has probably the finest page layout capabilties of any multi-function imaging app, but it isn't a RIP. It still uses the operating system and the printer's driver.
Personally, I think that a decent printer manufacturer should supply a driver capable of producing good results from RGB files, and one should not need to buy an expensive RIP unless he/she needs Postscript or other specialized capabilities.
It seems as if everyone agrees that the Epson drivers are suboptimal. Are the Canon drivers on the new model you just tested any better?