Buy iRobot Roomba 630 or 780 which is better? Find the difference between them and get the one that meets your needs best.

Roomba 630 VS. 780
images from manufacturer

Price: the Roomba 780 is much more expensive at this moment.
At irobot.com, Roomba 780 is priced at $599.99 whereas the 630 is priced at $349.99. (on 2013-02-02)

Scheduling Option:
The 630 has no scheduling option whereas the 780 can be scheduled to vacuum.

Virtual Walls and Virtual Wall Lighthouses:
The 630 comes with 1 virtual wall, but no lighthouses; while the 780 has 2 lighthouses.
The virtual wall can only confine Roomba in a room; whereas the lighthouses not only confine the robot to vacuum in one room, but also direct it to the second room when it finishes cleaning the first room, they call this Room To Room Navigation.

Control Panel:
The 780 features touchpad to control while the 630 can be controlled by pressing buttons.

Dirt Detect Technology:
The 630 features Dirt Detect while the 780 features Dirt Detect Series 2. The Dirt Detect uses acoustic sensors to locate dirt and debris whereas the Dirt Detect Series 2 uses optical and acoustic sensors.

Remote Control:
The 780 includes an infrared remote while the 630 doesn’t.

Bin Type:
The 630 uses the AeroVac bin, whereas the 780 uses AeroVac Series 2 Bin.

Full Bin Indicator:
The Roomba 780 features a full bin indicator to tell you when to empty the dust bin, while the 630 doesn’t have the indicator.

Filter:
The 630 uses AeroVac filter whereas the Roomba 780 uses Dual HEPA filters to trap tiny particles as small as 0.3 microns.

Extra Filters:
The 780 comes with 1 extra set of 2 HEPA filters whereas the 630 comes with 1 extra AeroVac filter.

Brush Cleaning Tools:
The 780 comes with 2 brush cleaning tools whereas the 630 has only 1.

Extra Brush Set:
The 780 comes with 1 extra side brush, 1 bristle brush, 1 beater brush whereas the 630 doesn’t.

Persistent Pass Cleaning:
The 780 features a Persistent Pass Cleaning Pattern, it uses a back-and-forth cleaning motion that mimics the way you vacuum, whereas the 630 doesn’t.

Dimensions:
Dimensions of 780 is 13.9″ in diameter, 3.6″ in height
Dimensions of 630 is 13.39″ in diameter, 3.62″ in height.

Weight: The 630 is a bit lighter.
The 780 weighs 8.4 lbs, whereas the 630 weighs 7.9 lbs.

If you know more difference between iRobot 780 and 630, please share.