To diesel or not to diesel

I've been holding out for a nicely maintained 1985 300TD. I have the opportunity, however, to buy a 1991 300TE with 156,000 miles at a very good price. I know the gasoline engine doesn't have the reputation of the elder diesel, but will it provide reliable and cost effective transportation (I commute about 20,000 highway miles each year). I've heard for years that the diesel will go hundreds of thousands of miles. In contrast, what can I expect from the gasoline?

Thanks in advance!

Matt
'99 C230