Euribor is always generally higher than ECB rates as it is an inter-bank rate and therefore reflects the extra risk involved on top of the base rate offered by the ECB. Under normal circumstances, it would not be much higher (about the 10bps I suppose but hard to say and haven't looked at the historical data) but as you said yourself at the moment, it is an awful lot higher due to liquidity concerns. Personally I would always pick the ECB tracker rate. I would say it is more in the banks interest to lend to you at Euribor+margin.