No the biggest problem is the memory leak in deed, a client which gets slower and slower after an amount of time is instable, it cant be stable otherwise you dindt get these performance issues.
Maybe they are also doing something in the background against it, i would also say performance and the memory managment in all areas also effects is the main problem with the client. If they get this fixed, the client is nearly ready for release, art updates or interface tweaks can always be brought in.
I dont know why it is soo hard to get it done, maybe they should use the connection to the WaR developers same engine, maybe they know why a memoryleak is caused.