Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: what are the main differences between the 780 and the 770 iRobot Roomba?
Document: **These are the main differences between the 770&780 and as such I have used much of the same from the reviews of each because they perform the same minus these few features**Is the Roomba 780 worth the extra 100$?If you have multiple rooms that you want the Roomba to clean then yes, I would say go for the 780, which has the 'lighthouses'.
Comparing the ability to clean and operate between the 770 & 780 is essentially the same--as they are basically the same product except for a few things:780 has touchpad controls whereas the 770 has physical buttons.780 uses 'virtual lighthouses' to direct the Roomba where to clean.
I own this and love it it picks up so much dirt in my brand new apartment it's crazy! So far I have not had the need to purchase an upright vacuum, once a week I just sweep the corners... Roomba is round . :). OOPS mine is the 770 so I can only assume this 780 is much better. It's sucked up so much dirt, no idea where it came from???
Highly recommended. This top of the range Roomba 780 lives up to expectations and MORE..., April 6, 2012ByAgogo - See all my reviewsThis review is from: The Dirt Detecting Robotic Vacuum. (Kitchen)Inset pic shows the top of the range model from the new roomba 700 series, comprising 760, 770 and 780.
The 780 is the top of the line Roomba robotic vacuum and comes with all the bells the whistles. Questions that might be asked are:1)Is a Roomba right for me?2)Should I go for the 780 over the 760 or 770?Let me address question (1) first: Is the Roomba right for me? My thoughts on the Roomba are this. It is a great little automatic vacuum/duster but it isn't perfect.
Note: I uploaded four photos to support my review in the image gallery. Click on "View and share related images" on the top left under the main photo to see them.I wish I wasn't writing this. Oh how we wanted this robot to sweep into our home and change our lives, just like we wanted our Roomba Red to do way back in 2004. Unfortunately we were left just as disappointed with our new 780 as we were when we bought a Roomba Red eight years before.
My first maintenance took about 15 minutes because I was working out what to do by watching helpful videos on the UK iRobot site. One complaint I have here is that the 780 manual does not really give clear instructions on how to clean the Roomba and it also doesn't direct you to these videos.
The say a dog is a mans best friend, that's true until you have to vacuum up after it every day. The iRobot Roomba 780 is our new shining star in the house. Now I can hardly wait for the new Roomba 666 release with the turbo pooper scooper add-on option.
Whether you think the price difference of $80-100 is worth the upgrade is your call.Roombas 770 and 780 offer a better upgrade with a redesigned dirt detection system 2 (noticeable improvement) and a bin full indicator. Model 780 has the further upgrade to touchscreen controls which to me is redundant (more electronic parts means more...), comes with two lighthouses and is shipped with additional filters/ brushes.
Here is my comparison review of the Neato Signature Pro, iRobot Roomba 780, and the LG Hom-Bot Square. I bought and tested all three, and ended up keeping the Neato and returned the other two. Here are the details of our comparison and review of each model:iRobot Roomba 780 - It is one of the dumber vacuum robots on the market, because it lacks the more advanced navigation abilities that competitors have, while costing more than some of them.
Answer: They are very similar. I have the 780. Here are the differences I found: 1. Virtual Wall® Lighthouse on the 780 is different that the mere Virtual Wall on the 770. The virtual wall simply contains the Roomba in the room. The Virtual lighthouse does 3 things: a) it contains it in the room just like the Virtual Wall; but then it b) allows it to go to next room when first is complete, and c.) serves as a 'lighthouse' so Roomba can find it's way back to the docking station when it is 'out of sight' of it in the next room.2. The buttons on the 780 are 'touch keys' whereas I think on the 770 are 'buttons'3. The 780 has a 'trash bin full' indicator.A pretty good comparisoniRobot Roomba 780 Vacuum Cleaning Robot for Pets and AllergiesI personally have not yet found the differences to be worth it. I may figure how to use the lighthouse thing more later, but for now in my situation the 'next' room is 'under construction' and we are not having Roomba go into there. Also the primary room is a large 'great room' ... 750 sf, so Roomba may be out of juice before it could do the next section anyway. If you simply want it to do one room at a time, no need to go to the 780. If you have multiple rooms you want it to automatically do, and they're not huge, a lighthouse at each door may help.I was new to this technology when I purchased. I will try these out when our 'next room' is completed (within the next month or so I hope). If these Lighthouses do not add significant functionality here, then I'd definitely go the 770 cheaper route next time.Full bin indicator - if you empty it every time between used, not worth it unless maybe a lot of dust, pet hair that could fill it up before a room is cleaned. (info chart is a little confusing on whether the 770 has this or not.)Touch keys .. your call. I wouldn't pay for the difference.