A good way to think about crash bungs is that they are like a crash helmet, they wont save the bike from everything, but they will keep damage from a low speed drop to a minimum.
As for the asthetics of it all, think about this. It took Triumph months to design the beauty that is the ST, it took God one day to create mankind, this was at the end of a very long week and he/she (don't want to upset anyone) had probably had enough by then and didn't do a very good job on most of us. If you're anything like me - wrong side of 40, a taste for beer with all that that entails, questionable taste in bike gear and a face with an alarming resemblance to the back end of a bus and what do I go and do? Go out and buy an ST and sit on it. It makes the question of if the crash bungs ruin the look of the bike pale into insignificance.
Charlie2