Keep in mind that almost any new/newish MB is going to be nearly flawless for tens of thousands of miles - then the floodgates of expense in repair out-of-warranty starts. My '99 E300 bought new was a joy for a few years with no issues either, before it started costing big repair dollars. Of course the warranty had long expired on it by then. These are not cheap vehicles to keep on-the-road, other than their fuel economy, and even that doesn't get entirely mitigated by their unavoidable repair expenses as they age. What the OP described sounds to me like a creampuff used model with a full-warranty included in the sale.

However, it should be noted that in our family's experience in buying new MB diesels over the decades, virtually nothing goes wrong with them in the first 100K miles if you put those miles on it within the first couple three years. In fact, we had no issues putting 175K +/- miles on our '60s 220D and our '70s 240Ds. However, those miles were put on them in their first 3-5 years of ownership.