Buying Combo Diesel – yes or no?

Hello guys and girls, after Glattiskrash with total damage I am autoless and urgently looking for replacement…. So far I have been driving Seat (Arosa) but now I want something bigger. On the topic of box vans my research has revealed that compared to other brands the Opel are apparently quite undisturbed….about 5litres diesel/100km. I hope this corresponds to the reality. When asking different people different recommendations came out from: “Opel Combo is not at all – the M otoren are crap” up to “Yes Opel Combo is great, can buy quietly”. Confusion total. Alternatively, in Renault Kangoo is in question. Who can call me plus and minus on the combo? I would like to have either the box (with flex separation grid), preferably two sliding doors. For transporting my dogs (boxes) and sometimes for penning in it. Thanks already in advance for your help!