I use the 2500.....
You can play around with the settings to see what you like best. Straight is what I use 99% of the time. Pure Direct is supposed to be best for 2 channel music, but it doesn’t have a sub output, and it skips the EQ system. Depending on your speakers and tastes, you may like one over the other.
Do you have a sub?
Do your speakers give you enough bass without a sub?
Does your room have any acoustical problems that would make you need the EQ?
All things that you’ll need to answer for yourself.
As far as all the music settings, they are fun to try, but I wouldn’t use them for critical listening. In the end, it's up to you.