cjoseph, thanks for the reply.
> What application is being deployed?
1. The most important is skype video-conferencing. It is not used all the time but when it is used, it must be good. It is business critical app.
2. HD video watching. It is not used all the time but when it is used, it must be good.
3. Most of the time it is web-based apps like office365, dropbox-sync, etc.
> What are the capabilities of your clients?
About 10 vaio notebooks support 2.4 GHz, AR9285-like adapter
About 10 notebooks are mac air or pro. Support 5GHz MIMO.
The other 10 are mobile devices like iphone or ipad.
The goal is to design a really stable wifi-infrastructure. Without any excuses. Is it possible? The people are tired of unstable wifi. They want their 20 mbps (when they need) and stable video and audio conferencing.