Welcome Stu, as said above - the Triumph panner bags are excellent quality and hold a surprisingly amount. The small rack is useful, but it's difficult to find a small bag to fit it, for that little bit of extra carrying capacity. The most important mod for me was slackening off the handle bar clamps and raising the grips by 30-40mm and then adjusting the levers & master cylinders to suit. For me it made a massive difference in the riding position (on my GT). The other big item for me was the flyscreen, the standard screen has no effect at all. I looked at all the replacement screens and considered them "Fugly" and so just made some mounting brackets to raise the screen to do the job. I used 2mm aluminium and painted them as close to Storm Grey as I could get. Nobody even notices them, saying the look factory ! They work well.
The quickshifter is a waste of money for me, as is the the conectivity unit !