I just got my first set of D'Addario flatwounds and was very impressed. They advertise them as having a very mellow tone, and that's an understatement. You won't want them for every application, much more thud than high end. But lots of heft and they feel great under the fingers. I've got them on my Modulus 5-string, so no problem with reduced definition, but YMMV. and the 0.132 low B string is huge.