I've had my GS for one year and done 13,500 ish miles, excluding taking it off the road when all the salt was down. Used the Honda instead, so milage is a relevant issue to me, I've read that these 020's won't last as long as the Tourance, & as I use it to commute 46 miles to work each day ( on the motorway) tyre wear is highly relevant.
The odd wear pattern felt odd, but wasn't unsafe, so I carried on until it was shagged. Does that make you a girly ? or me a tightwad?
Strangely enough, the front Bridgestone on the Honda CB1 400 is wearing the same.
Welwyn Garden City, there's the clue, must be off road in all those gardens.