I realize this is a somewhat old thread, but with the increasing popularity of these things and DH being written for them, I thought I’d add my two cents.
I have recently tried 2 different models; the Shark irobot 750, and the Neato Botvac D3 Connected.
The Shark was a dumb machine, no particular smarts to the software. It roamed around aimlessly until the battery ran low and then that was it until you recharge it and start again. Many missed sections of the floor.
I replaced it with the Neato. This work far better for essentially the same price. It has mapping tech and moves around the room in a very methodical manner. You get a map of what was vacuumed. Virtually no missed spots once it is finished. For large areas, it recharges itself twice if needed to finish the job.
Alyc100 has written a very helpful DH and ST app for this brand.
I hope this helps folks looking to purchase a robotic vac.