After reading the specs for the new RB333 boards, we were very impressed. Our StarOS WAR boards (IXP425) were beginning to see high latency and dropped packets at peak hours, and we were starting to shop around for options.
Our WAR link was running in turbo mode, using Ubiquiti XR5 radio cards and Super A/G mode compression/fast frames. We would see roughly 20 mbit combined up/down across the link at peak hours, and these seemed to be the limit of the boards. They were doing static routing only (StarOS does not properly support OSPF, another reason for the switch), and no connection tracking.
We started by replacing the AP, which did not talk very nicely to the StarOS SU (high latency) - so we promptly replaced the SU. The RB333's were preconfigured for a fairly standard AP/SU setup - compression off, NSTREME off, turbo mode but otherwise standard settings.
The first issue we ran into was on the SU, we have a roughly 200ft cable run (armoured STP) - and it appears with an 18V power supply, the RB333 would not run two Ubiquiti SR5's properly. Removing one of the cards worked, and we later installed a proper industrial-grade regulated 28V power supply, which cleared up any power issues.
In a normal AP/SU scenario between the two RB333's, we were seeing hardly any packet loss - but very high latency, roughly 250-300ms on average. The available bandwidth seemed to be very low. We tried changing almost every setting (compression, preamble, frequencies, ACK timings, etc.), but to no avail. We are pushing about 20-30mbit and 5500-8000 packets per second over the link.
Eventually, we turned on "NSTREME", "Polling", and "Framer Size: Exact Fit" - and this immediately solved the problem. The link is now 9-10ms latency solid, and has absolutely no issue handling the load at peak times. We are quite amazed at the performance of these little boards, and are looking at replacing the majority of our backhauls with them. We are also looking forward to trying NSTREME-DUAL when this link starts to run out of capacity as it is.
Overall, very pleased with the performance of the boards - once they are up and running. Getting them to run was a bit of a challenge, and we're chalking that up to the beta firmware. Perhaps there are some quirks in the standard 802.11 stack, that are overridden when NSTREME is turned on.
The link is roughly 12km long, and has roughly -52 signal strength (on two 4ft dishes).