I did 10000 miles over 9 months and I averaged 59.9 in mine, brimming it each fill and recording mileage via an app (rather than via the dash info). I did, however, cruise at 63mph on motorways and 85-90% of my journeys were up at down the m1 for work. I rarely got under 600 from a tank but obviously I drove it relatively slowly! The one time I did give it some beans on a 100mile trip back from Skegness at almost midnight when the roads were empty, I 'only' got 550 from that tank.
Change of job means I've now got an Audi 1.8tfsi (same engine as the leon 1.8 which I would have got had there been any in the right spec/price band at the time I was looking) and I'm averaging 38mpg over 3 tanks so far over 2 and a bit months so you can see my travel has dropped drastically!