I flew ORD-TLV-ORD in March and on both legs LHR-TLV-LHR I was complimentary upgraded. On the LHR-TLV they told me the plane was very full so they moved me up. On TLV-ORD I asked at check in if there was any opportunity for an upgrade and when I got to the gate the same agent who had checked me in handed me a new boarding pass. Never hurts to ask. Compliments to the BMI staff in both LHR and TLV.