Irobot, the same people who make military robots being used in Iraq, have released another type of robot that aims to invade your home. Unlike the war machines in Iraq, this new robot is aimed at cleaning up the mess in your house.

I previously reviewed the Irobot Roomba Red some years ago and found that it was indeed a capable machine but it was plagued with reliability problems that kept it from doing its job. The new Roomba series is called the 500 series and this line is supposed to cure the previous Roomba's ills as well as add signifcant gains in durability and functionality.

The 500 series of Roomba comes in several different models with increasing price tags along with higher features, though all of the 500 series Roombas having the same basic cleaning and robotic features.

The 510 series is the lowest in the lineup and it lacks some features such as a scheduler, automatic virtual walls, and a self charging base though it sells for more than a $100 less than the highest model. Since the overall cleaning mechanism is the same this review should apply to all models of the 500 series.

The best way to maximize performance from the Roomba is to confine it to one room at a time. The 510 comes with 1 virtual wall which transmits a beam to prevent roomba from going to or leaving an particular area.

Like its older brother, the Roomba 510 starts off by going in a circle. This is presumably done to gauge the size of the room. Once the Roomba comes into contact with an object it then starts off in a pattern of cleaning cycles. At first it appears to be random but the Irobot designers have programmed quite a bit of intelligence into the little bot. If allowed to run until it automatically shuts down, the Roomba will cover 99% of a room even if the room has many obstacles.

The roomba does take a lot longer than a conventional vacuum does. Typically I am able to vacuum a room in about 5 minutes where the Roomba can take 20. This can be maddening if you sit by and wait for the Roomba to finish (or if you sit and watch it go around and around). The best way to use the Roomba is to set it in a room and go do something else.Once the Roomba is done with that area then you place it into another area and let it do its work while you do yours.

The more expensive models (560 and above ) come with a scheduling feature that allows you to program when the Roomba should go about cleaning. The models from 550 and above have upgraded virtual walls that automatically allow the roomba to leave one room once it has completed vacumming so it can go onto the next room. All models from 530 and above have a self charging base so the Roomba can automatically return to its charger for its own R & R once it has completed its task.

Overall, the Roomba was able to easily clean carpet and pick up large particles (such as bird seeds) as well as smaller particles such as sand and talc powder. One nice feature carried over from the older model is that if the roomba detects that there is a large amount of debris in one particular spot it will continue to circle that area until clean.

If your house also has hardwood or laminate flooring, the Roomba easily transitions to these surfaces and does an admirable job cleaning without scratching. The brush is definately softer than the older 400 series (or even a normal vacuum) so it should not have a problem with scratching most wood and tile surfaces.

A single charge should be good for about 3-4 average sized rooms. I generally stop the Roomba short of its full cleaning cycle (it seems to go on a bit longer than is absolutely necessary) and I am able to almost clean the entire first floor of our home (about 1300 square feet). This includes carpeted bedrooms, laminate floors and hallways, and tiled kitchen and entryway. Once drained, it takes about 3 hours to fully charge the Roomba.

Apart from the previously mentioned modular construction, the newer series has the following advantages over the older Roomba:

- a better sidebrush with more arms

- the ability to slow down when it detects an object is near (this is nice because it cuts down of the "whacking" sounds you heard when the old Roomba crashed into obstacles!)

- Anti- tangle technology so that roomba does not get stuck on cords or tussles.

- New programming that helps the roomba to get out of a situation where it is stuck in a small space (such as under chair).

- longer battery life and quicker charging times

- Ability to follow walls and make turns when the wall turns.

- Voice guided help menu and troubleshooting

Although the Roomba cleans like a normal manual vacuum cleaner, it definately requires more maintennace than a normal cleaner. Every time you use the Roomba you will need to empty the dustbin and clear its filter. This is not at all difficult to do and is actually sort of amusing because it lets you know how well the Roomba is cleaning.

What is not amusing is that once a week you will need remove Roomba's main brush and remove any hairs that have accumulated on it. With my house having 3 females with long hair, this can become a frustrating task involving scissors to cut away the tangled hair. It is not difficult to do, and it only takes about 15 minutes but unlike a normal vacuum, this bit of maintennance cannot be ignored or it will decrease the performance of the Roomba.

During my 3 months of use, I have not had any failures or major problems with the 500 series Roomba. I did call Irobot to replace the screw that was holding the side brush (it fell off because I did not fully tighten it after I took it apart to see how easy disasembly would be). Not only did Irobot send me a new screw but they sent me 3 new sidebrushes!! In a world of increasingly cheap companies with shoddy customer service, it is nice to know that the folks at Irobot truely value their customers and go above and beyond to try and please.

The Irobot Roomba 500 series is a significant improvement over the older model. It allows for much greater reliability and durability while still maintaining the ease and automation of the first generation.

The cleaning ability is still comparable to a normal upright manual vacuum though the cleaning times are much longer. Another signifcant problem is that because this is a high tech device you will need to spend a great deal of time in cleaning the brushes and filters or the cleaning performance is degraded signifcantly. At least every few months you may also need to dissassemble some of the other modules in order to clear away any dust or debris that finds its way past the protective bottom plate. This is not something terribly difficult to do but it is not something that your 80 year old grandmother will find enjoyable. For this reason alone, it appears that the Roomba series is made more for young professionals rather than older retirees (unless they like tinkering with gizmos).

Although the higher models have some pretty nice feature upgrades their price is significantly higher so unless you absolutely need the scheduling and the multiroom abilities the 510 and 530 models seem to be at the sweet spot of price and performance.