Don't want to take this further off topic, but an interesting comparison: Haken vs Transatlantic
Transatlantic obviously has their influences, and so do Haken.
TA's sound hasn't really shifted in sound like Haken's has. TA"s evolution has been more gradual and more of a maturing process.
TA hit the ground running, just like Haken. TA more influenced by 70s prog, Haken more influenced by 90s prog (metal).
When I want to listen to TA, or Neal Morse, I know what I'm getting into. Roine Stolt not as much, TFK have mixed it up way more than Neal. When a new TA or NM album comes out, I know what I'm getting into. If a new album comes out and I'm not in the head space for that style of music, I take that into account when I listen, or I just hold off on checking out the albums until I'm in the mood again. I'm not always in the symphonic prog mood. Stylistically, however, Neal Morse basically puts out the same albums every time. It's always exciting, though, if that's the music you want to hear. It takes others around him to shake it up, which is why Transatlantic is almost always some of the best Neal-related music out there. All that said, I respect the musicianship and enjoy the melodies and the occasional riff and the general "epicness" of it all, so it doesn't bother me that Neal's music hasn't evolved much over the years.
Changing your sound drastically album per album, or every 2 albums, has it's inherit risks of turning off fans. Some will obviously be along for the ride.
I'm totally into bands mixing it up a lot on each album, but for me, Haken's last two albums were "samey" compared to one another, and I didn't like the overall sound the first time, so to keep that feel of the music going a second time, had me giving up on the band (not to mention lack of keyboards.) If their last album was different from the previous, or more like their early stuff, but maybe harder or heavier, then I could maybe go back and appreciate Vector more for what it is, but if the band is staying in this space, musically, I'm out, and I'll always have the first 4 albums plus demo and EP to enjoy.
I'll try to give Haken's last 2 albums another go some time soon, hopefully, so I can maybe update my opinion on those albums since it's been a while. There is always the issue of not being in the right head space for a band's music when they change and you were hoping for more, or something else.