Depends how harsh you're driving it in fairness, motorway speeds will start to drink and drink fuel. You should really get your front lambda checked that voltage is OK and switching in good time, eBay MAFs are OK but not as good as the real deal (mine was swapped 3 times in total!). Juddering idle on mine was caused by an air leak in the throttle body/vacuum pipes but mine was to the point where the steering wheel was vibrating harshly and revs were down to 550-640.
Also check basics, tyre pressure etc.? I've been getting about 35MPG on my 1.4 manual with similar mixed amounts of driving despite all my issues recently and long term fuel trim hanging around 20-23% so I'm hoping to see an increase in MPG when it drops down again. If you've had an EML code come up just before it was serviced it will still be in the history probably if you get the ECU read.
