I realised I've misread your post, you were only asking for disadvantages (or the lack there of)!
With the creation of the different joint ventures, this one has gotten even stranger.
Originally Posted by
ffay005
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Upgrades: not available on codeshare, only AY metal and AY flight number
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The principle still is the same, but suddenly there are more codeshares and AY is more aggresively pushing tickets on non-AY-metal, adding confusion for it's memberbase.
Sadly, the JVs only covers revenue sharing and ticket sales. In my fantasy world, they should have included FF-stuff in the deal. AY+ members should have been able to do upgrades on all JV-routes, earn points according to AY table et.c. If they did that, then it truly would have been positive for us customers.