Not at all, I have over 100k of ownership experience in W115 Diesel powered cars. They were fine cars, and I actually prefer them to the later W123 series, but the basic W114/W115 design comes from the mid 60's. By today's standards they are pathetically slow (almost to the point of being dangerous in heavy urban traffic - 0-60 times will be in the mid 20 second range), not really all that fuel efficient, have marginal HVAC systems, terrible rust protection, no airbags, no ABS, no traction control and no ETS. As the lowest cost four door sedan in the product offering line they really won't really have any status as collector cars anytime in the near future.

I guess it depends on what you want to do with it, I would never consider one for daily driver duty but I guess it would be a good candidate for a low-rider conversion.