Hi,
With the DEC modifier you can specify the number of digits to send and even "print" signed number with SDEC - neither of which you can do with the #-modifier. That extra power/feature comes at a cost.

DEBUG is "leaner" because its parameters (pin, baudrate and mode) are set at buildtime (by the DEFINEs). This means that the timing is calculated at build time and programmed as constants. When you use SEROUT you can change it and runtime which means that the timings needs to be calculated at runtime, at a cost. SEROUT also supports more modes (open vs driven) than DEBUG does.

If DEBUG and # provides you with what you need there's absoultely no reason not to use it.

/Henrik.