A brief recap: in Part 1, I talked about what 802.11ac can provide and left it asking whether we should invest in 11ac.
If you are in a greenfield (new) situation, I would recommend 802.11ac. Even if you do not need the technology at this stage, newer devices will have support for it and will be able to take advantage of it if it is there. The population of client devices in your organisation supporting 11ac will only increase. This is a natural progression, as newer standards become the norm.
If at present there are only a few laptops that support 11ac, for a small percentage of the user base, a costly redesign and upgrade exercise may not make an adequate return on investment.
I touched on caveats in Part 1. One of these is that in order to reach the highest speeds, your environment may require that you deploy larger numbers of Wireless Access Points than what you have now. The reason for this is that the particular speed increases that look so attractive require no obstructions (e.g. walls) between client and Access Point. More Access Points may be required to service the same number of users today.
As each business environment is unique and by that I mean not the organisation as a whole but each location or operations within that business may have different technology in use and operate in different environments. For example a warehouse vs an office vs on-board a train or a ship, etc. Should a particular environment not lend itself to the performance enhancements that 11ac offers, then it may be a difficult sell to push for an upgrade.
One option is to wait for Wave 2 before any significant investment is to be made. Wave 2 promises something Wi-Fi has not yet been able to do: deliver data to more than one client simultaneously. It may seem that it does that already, with a group of you sharing the Wi-Fi in your office. But what the wireless service is actually doing is slicing up the airtime at a very fast rate (in microseconds) and sharing it between you, so that it appears as if you are downloading at the same time. With 11ac Wave 2, you actually will be.