I'm fine with Hayter. While not the greatest performance, the voice is at least memorable. I remember reading an interview with Frank Welker who voiced and still voices Megatron for the Transformers cartoon. They asked about his opinion on Michael Bay getting Hugo Weaving for the Transformers movies while keeping Peter Cullen from the cartoon to do the voice of Optimus Prime. He replied that while he wishes he was asked, he understands why his melodramatic and over-the-top Megatron voice wasn't chosen. However, when conceiving the Megatron voice for the original cartoon he knew it had to be iconic and distinct for the audience to really connect with and separate the character from the other Transformers in the series. I don't think anyone really recalls Megatron's voice from the movies, but they sure remember the voice from the cartoon.
Hayter's Snake is distinct and his inflections are individual to the character. That is what I think will be lost with Keifer Sutherland and it seems like he is just doing his regular voice. It'll definitely be something I'll have to get used to. But I will say, as "bad" as some of Hayter's VO can be throughout the series, there is a lot of nuance and some real great performances from him--especially in MGS 1,3,4. I think a lot of people are misremembering his Snake as the gravely MGS4 voice without the proper context.