Is there any resource that compares the four brands?
You can probably find comparisons between any two but you'll have to search them out... Gartner might have somethign basic.
here's a quick hit though on handy dandy features.:
Ruckus - Unleashed firmware and firmware updates are free as in beer - so long as you are willing to give them (Ruckus/Commscope) an email address that can be validated for the login. IMO a very small price to pay given throw-away accounts are easy to get.
If coupled with the right brocade switch (7150,7250 for sure) you get some tie in to the unleashed management page though I have not played with that yet. Some AP models can also do lag if you are into that sort of thing.
Meraki - cloud managed infrastructure, works, designed for mostly non technical people to get good management/feature mix. Tends to be expensive and/or maintenance required
Aruba Instant On - I don't really know a whole lot about this.
Cisco Mobility Express - you will have to search for firmware in the dark recesses of the Internet-webs, its find-able, but you are violating all kinds of laws (copyright/theft of service) or so "they" say by "stealing software" . Also I have heard a kitten dies every time someone downloads cisco router code - but that could be an old wives tale.
Okay so more seriously. Read the Ruckus thread ... see what folks think who left UBQ... Mapping SSID's to VLAN's is brain-dead simple. Supports 1:1 SSID to VLAN or N:1 SSID to VLAN if you need that too. Periodically a treasure trove of Ruckus R710's find their way to the bay and sell for 210-250 each - you'll see that in the thread. There are older models as well and a variety of models by use case, indoor, outdoor etc.
the antenna technology is REALLY good.and seems to cut through the ever present horde of SSID's that we are now plagued with. My iphone will still be connected to my network from outside and half a block down the street. Then again I have 3 AP's.
I used to run a Cisco WLC and 3 AP's. They're in a box in my basement now.