Don't know if there was a "worst" Amiga but the A4000 was the most dissapointing, I had been expecting 16 bit sound at least but it didn't change at all. Now we know what they were working on and what it really is (a glorified A3000) so it's even more dissapointing given what it could have been.
As for the A1000 I was using it last night, it doesn't make that much noise until you do something with the disc drives which are dog slow and can make quite a racket!