So far, my EuroBonus card is weak. 25% mileage on too many classes of service at charges which would definitely get me 100% mileage on other cards is my biggest complaint.
For a dear friend, expiring points was a serious issue last year - and he was unable to gift those points to his wife's account so she could get an upgrade to come back to Sweden from the USA, though she was shy only 1000 points herself.
I'm still trying to figure out if a stay at a Radisson Hotel qualifies for a few extra points on the card - the hotel said no, but the card information claims yes. While I'm not going to suffer over 500 points, it will definitely be a negative point for EuroBonus.
Half-point tickets for teens is a plus. It is highly possible I will take full advantage of that as soon as I have enough points to use. My fear, however, is that the rule on teens will change by that time.
At the moment, I simply don't have a selling point for EuroBonus - however, my membership is still fairly new.