I use midi files for several instances where I need more automation than styles provide, and yes, I could use the chord sequencer IF I use my PA4X. With the Pa4x, I am playing and singing with styles, but sometimes play SMF files and read the lyrics and notation right on the machine. No need for laptop here, and it is very accurate with customizable key signatures.

Recently, I have found another use in adding harmonica to my repertoire, which has been very well received. I am very good at playing any song,within reason, I know by ear, in any key. There are times with small venues when I need the the least amount of equipment I can get by with. To wit: SD40, mic, and the smallest controller to midi to the SD40 in order to play alternate melody with the harmonica. All I have to do is go to my favorite instruments folder for a quick choice of lead instrument as the midi is playing(melody muted). I, normally, play both hand split, but can get by with melody only with SMF.

Now, let's go a step farther, and say I want to play styles with the SD40. No problem with the SK1, but, if I want a minimal footprint, I still need a controller big enough for left chord and right melody. How small can I go?