While the general idea for Beast Machines was pretty flawed to begin with, I thought there were some good spots. There were indeed a lot of pointless character and philosophy changes, but I could appreciate it as a standalone series. Finding out the fate of the various Beast Wars characters and the cause for Megatron's rule over Cyberton is what kept me watching. There was just too many bad things in Beast Machines to even compare it to Beast Wars. I got to talk to Scott McNeil at one of the anime conventions last year, and even he vocalized his disdain for Beast Machines.
As for Beast Wars, I think that's been pretty much covered.