Whilst on the subject of serial decoding, this time I2C, I would suggest the following improvements:
1. The Address and Data fields both start with repeated titles and are left justified, so you need to zoom in rather more than necessary in order to see the ACK. I would suggest removing the repeated word and centre justifying the text. (See attached image).
2. Decoding significantly slows down the capture. It would be nice if there was a way of quickly enabling and disabling the decoding. Currently you have to go through the menus and set the decode to none to disable and reselect the protocol to enable. A check box on the Serial Decoding panel would be great!