I like doing both, for the time being anyway. Of course, there will come a time when I run out of dumbells, and this would be inevitable for most lifters I guess.
They "feel" different, and it seems to me DB bench works more chest, or works it differently, or something.
41yo, 6'2", ~96kg
best lifts: sq 160kg / bp 115kg / dl 195kg / c&p 80kg
my training log