Depends on what you're talking about.
If you mean the modular cable system, yes. Having less cables in your system reduces heat absorption, increases airflow, and looks better due to less clutter. I prefer modular because I use only the cables built in plus 1 extra strand for molex to power my fans and SSD. (Besides right now, since I have my server integrated)
Wattage, that's a different story. Since Seasonic makes both the internals will be closer to identical. All single cards as of today can run on a 650w. That goes up to the GTX 690 which requires a minimum of 650w quality PSU. Most good cards as of right now require 550w or less which includes the 670 and such. The TDP of cards will only get lower as technology progresses. I tell most people you get a TX650w or equivalent and you'll be set for a few builds.