I don't see any benefit fuel wise vs the costly repairs they can incur. I was involved in the 900 series Tahoe/Yukon/Escalades when we offered the Hybrid. I learned so much from that project! I still get excited when I see one still on the road today! My shop actually had one come in because nobody else including their local dealership had anyone fluent in these. A customer told them about us and we got the truck and it was a 2009 and had 227lk miles. I was proud of that...it finally needed a new battery which was $3300 plus install. Not bad for the age and use. BUT a newer more advanced Hybrid has much more complexity and battery costs etc. So again - No I would not even consider one.
While I can see the benefit for the new car purchaser, I think we can take it as a given that the battery isn't going to last the life of the vehicle and therefore it going to be a very bad purchase for some used buyer down the line where the improved mpg does not begin to compensate for the battery replacement cost. I was reading that even mild hybrids have a 48V battery as the starter battery and that can also cost $3000 to replace. The car manufacturers haven't the slightest interest in making hybrid batteries simple and cheap to replace and for the likes of Mercedes it can be $10,000.
I'm actually looking to replace my car soon and as a low annual mile user I'm not that bothered about the last few MPG but I am concerned about simplicity and maintenance costs so hybrids and in particular a Mercedes hybrid is ruled out for me.