KirAsh4:
With the old 002x IDE, I always used an FTDI cable to upload code to an Arduino clone. I'd first burn the bootloader through Arduino ISP (using an Uno) and then proceed to upload sketches via FTDI (different com port). However with 1.0.1, there's the option to 'Upload using Programmer' (holding shift key down) and it sends the code to the clone (via ArduinoISP). However, I noticed a difference:When I upload via FTDI, the clone takes a few seconds after a reset to start the sketch.
When I upload using programmer mode, the sketch starts immediately after a reset (which I liketh a lot.)Why's that?
It's because the bootloader waits a while to see if the IDE is trying to upload a new sketch or not. After the time out the bootloader jumps to the users sketch assuming there is one to run from a prior upload. When using ICSP the bootloader gets erased and only the sketch gets loaded into the flash memory which then runs as soon as the chip is powered up or a reset is issued.
Now that the IDE supports upload using programmer option that is a very viable method to use for the reason you stated and getting back the small amount of flash space that the bootloader takes. Either way having a choice is great.
Lefty