Yeah, for the record, MB went to the V6 engines in all gas models starting from model year 1998, except the S- class sedans (W140), which continued using the M104 3.2 liter in-line 6-cylinder engine until 1999.
As for my .02 cents, the things to look out for would be the engine wiring harness and head gasket leaks.
Other than a/c issues, which all MB's have (new and used), there is nothing really significant to look out for.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".