The big issue with the Mac beta client, that has been in beta for 3 years, is old problems never fixed combined with new problems that have made the game almost unplayable for many Mac users. With all these combined Anet continues to not give honest and open information about the Mac client to Mac customers. There were times when Anet promised Mac specialist and that person would post a few times then disappear. Now Mac customers on the GW2 forum get the same generic response they have been getting for 3 years, "We know there are problems. We will tell you when we have more information."
The Mac beta client, that has been in beta for 3 years, used to work decent. Something happened in the last 6-8 months that has made the client terrible and borderline unplayable if not unplayable at all. FPS dropped about 30-45% from what it used to be. Some people report not being able to launch the client at all. There are more crashes and other graphical issues than ever.
All the while Anet refuses to communicate openly and honestly with their Mac customers. Their own page about the Mac client, granted it is 3 years old but the first search result on Google when one searches for GW2 for Mac, states how Anet staff are excited to play on the Mac client, how the Anet president is always with his Macbook and how the client will work better when the final version is released (3 years now and no significant changes). It is a page that is misleading at this point to potential Mac customers who may search to see if GW2 is for Mac.
I do not think most Mac customers expect an overnight fix or a fix anytime soon given Anet's track history with the client. However, many are looking for more honest and open communication about the state of the client.
Oddly there were a couple of cases over the years where Mac customers could not buy gems or use the gem store and those complaints received a decent amount of attention from Anet and got fixed. Maybe the fix was easy for Anet to do with,at the time, TransGaming now sold to NVIDIA but they did garner a lot of red posts at the time and timely fixes. Now with NVIDIA buying TransGaming the client may never see any attention. A statement from Anet on this would be appreciated by their Mac customers that bought GW2 core and HoT based on Anet's claim to support the Mac beta client.
Edit: In fact Anet still claims on their HoT sales page that HoT works well with certain Macs when many people on the GW2 forum who have Macs well within those requirements have reported major problems, huge FPS problems and crashes.
http://buy.guildwars2.com/store/gw2/en_US/html/pbPage.heartofthorns