I am interested in OS - how is it better than AC or LH or LX.

First of all, for Aeroplan award tickets, there will be surcharge for OS and LH and AC tickets, but not LX (I have not figured out if SN tickets get charged or not).

In terms of the seats, AC has the true horizontal flat bed in private pods (some list of business class seats calls it an open suite). How do beds in LX vs LH vs OX vs TK compare from their Canadian city routes to their European destinations, and then from their European city destinations to DXB.

How are their departure lounges?

have once visited the LH arrival lounge in FRA - but one has to fly business or first class with LH (or UA or US) to get into that lounge. I have flown on LX once into Zurich - I visited the LX arrivals lounge. I would grade the LH arrival lounge to be superior to the LX arrivals lounge. Does OS have an arrival lounge in VIE?

Are there any Star alliance lounges in DXB?

How is the food and service on those airlines?