I have bought more than 10 Roomba's (all used) over many years. I have slowly moved them around for different jobs, older 5,6,700 series made their way to clea

I have bought more than 10 Roomba's (all used) over many years. I have slowly moved them around for different jobs, older 5,6,700 series made their way to clean the garage, while newer I, S models are working the upper levels of flooring and carpets. In the last 5-10 years it looks to me like they had two competing teams internally producing different models. The I,J series compared to the S series, are very different. The mops scooba vs braava. I really like their designs and repairability but if I had to update I would probably try one of the roborocks they seem to be a lot better.