WiFi is fine for my usage on the WRT3200ACM but I'm not a heavy WiFi user. Mostly just mobile devices on 2.4GHz which don't handle high throughputs anyway. I have no trouble maxing out the Wirless N speeds tho.
The WiFi driver for the WRT ist still in ongoing development and you will need to use a LEDE development snapshot to get usable and stable WiFi for the WRT3200ACM (newer Kernel + newer driver). The development snapshots will soon also include the latest version of the WiFi driver with support for proper signal reporting.
As an alternative you can get the latest LEDE stable and update the driver yourself from this thread: