For an external sequencer, regardless of the size of your setup, BeatStep Pro is a great solution.
indeed it is! and it's a keeper - ie it's always useful no matter how big your rack gets to... currently I predominantly use mine for sequencing song part/chord progression changes on my sinfonion - clocked from the sinfonion...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities