Depends on what kind of sequencing you want to do and what you think is friendly
There are soft sequencers that model x0x style sequencing, ones that model Moog style analog sequencing, ones designed to do algorithmic sequencing, etc.
Do you need linear, pattern based, real time, step only, piano roll, event lists, polyphonic sequencing of modulators (wheels and CC), etc?
I listened to Hatfield and the North at Rainbow. They were very wonderful and they made my heart a prisoner.