Well, I found the Andromeda more balanced thoughout the spectrum, where the Vega was more V-shaped. The Vega has a beautiful deep sub-bass though, which I especially enjoyed on genres like electronic & trip-hop.
Imo the Vega didn't sound that great from my Plenue 1 and Opus #1 (where my Andromeda does), but it was amazing from my LPG. That dap turned the Vega in an impressive holographic (3D) sounding beast. So I thought it benefitted clearly from the extra power that the LPG provided at that time. I wouldn't call the Vega more musical (in general) myself. But hey, that's just my opinion
I'm sure that both will certainly be a major step up in sq compared to your current se425. I had the se215 and se535 myself in the past, Vega & Andro play in a completely different league imo.
I also listen a lot to classic rock and the Beatles myself => that's also a reason why I stepped forward.
Good luck with picking the right one