No, you can not expect the same longevity from a 740 as from a Merc, imho (having owned both). Neither will do as well as a Lexus.
However, the 1999-2000 740 is the best looking BMW by far. Well, may be the 840.
That is hard to beat.
BMW 750xi 2012 Executive|Technology|SportM
Lexus LX470 2006 | Mercedes SL500 98 | Diamond DA20 2006