(Pocket-lint) - In the robot vacuum market there’s one brand that really punches above its weight in terms of value for money: Roborock.

Buying one of the company’s models is going to give a great cleaning, easy to use experience that doesn’t cost the earth. But there are still some things to consider, and a few different choices to mull over. So, we’ve got both the S6 and S4 in to show what the difference is between them, to help you decide what you need and what you don’t, and see if one fits you better than the other.

Now, both use very similar cleaning and sensing methods. They have that precision laser navigation system spinning around at the top of the unit to help recognise obstacles, walls and doorways. And that means both can create and save maps, allowing them to remember where they've been, and giving you the ability to tell them to go to a specific spot in the house, and do a spot clean.

One of the big differences is that the S6 can also automatically recognise and divide up rooms in the house. Once it's gone and made its first round and returned to the dock, it divides rooms up in the map, colour codes them and allows you to merge and edit boundaries where perhaps it's mistaken one room for two, or put the dividing line in the wrong place. Once that's done, you can set timers and schedule the vacuum to go clean a specific room at a specific time.

So the big difference, obviously, is price. S4 retails at $399, while the S6 is $649.

For that extra money you get a vacuum cleaner that seems quieter/easier on the ear as it’s going around doing its business. S6 also has a detachable mop module, which can lightly clean the surface of any hard floors.

With the S4, you get vacuuming only. There’s no mopping function. Then again, if you don’t see yourself needing that function. For instance, if you mostly have carpeted floors, then the mopping isn’t something that’ll work for you.

The S6 also has greater climbing capabilities. It can clear anything up to 2cm tall, so if you have fairly chunky threshold door bars, or thick rugs you may find the S6 does a better job of tackling those.

What’s really interesting about the S4 is that it has a more powerful drivetrain for reversing. So that means it’s actually better than the S6 at getting out of tight spots. If it gets itself all confused and stuck between chair legs, it’ll get out easier because its reverse function has more power than the S6 can manage. So it may just be the one to get if you have quite a lot of small furniture.

Other differences are quite minimal. S4’s charging connectors are right on the front of the vacuum, rather than be small precise ones on the bottom like S6. But it does have an attractive translucent to panel on the top, giving it a lovely stylish appearance, especially in black.Both vacuums have powerful suction and versatile cleaning brushes for picking up dust and dirt, and both have filters that are easy to remove and clean.

One other thing you get on the S6 is a “spot clean” button. Pick up the vacuum, put it down, press it and it’ll clean a small spot of the floor. It’s quite useful, especially under the dining table after dinner. The S4 can spot clean, but it involves pressing and holding one of the two buttons, it's essentially a secondary function and not as convenient as quickly pressing a dedicated button once. 

So there you have it. If you want all the bells and whistles, mopping and a nicer sounding vacuum, the S6 is the one for you. If you’d rather save the money and mopping isn’t as important, the S4 will do you just fine.