Hedonismbot sounds TERRIBLE - not like the original at all.
Okay, this took me a while, and I wanted to do it before posting in this thread. I've listened to every HedonismBot appearance in the new run, and compared it to the movies. I then listened to his appearances in Season 4. Just a few clips altogether. They're not vastly
different. In fact, if anything HedonismBot's fisrt
appearance sounds exactly the same as his most recent, with the slight variations occuring in between.
I'd suggest listening to HedonismBot in BBS, purchasing doomsday devices from Farnsworth first, then going to his short clip on the news in TLPJF. Those are the clips with the widest variation, IMO. He still sounds the same though. It's recognisably the same character's voice.
If you can grab the audio from all his appearances and string the soundbytes together chronologically, one after the other (I lack the tools for that at this moment in time or I'd do it for you), I think you'll be able to see what I'm talking about. Try listening to the clips with your eyes closed, so you're just concentrating on the audio.
The voice has evolved a little, but so have all of them. Listen to DiMaggio's Bender in the pilot, for example, then listen to him in APTR. There's a lot of difference there, but it's still recognisably the same character's voice.
The voices evolve as the artists revisit them. It can be seen in most long-running animated programmes. A good example would be the way Eric Cartman's voice has changed slightly in South Park since season one.