Also, we spent huge amount of time making sure uplink performance is top-notch, as is the general stability and determinism, i.e. jitter and tail latency. In the paper they show that OAI is quite unstable, and they only achieve 5-49% of theoretical uplink capacity.
Also note this is a tiny setup, single server, four simultaneous UEs (phones). The systems I worked with handled 20 000 phones per second, with quality guarantees, in environments like central Tokyo and midtown Manhattan.
So great for independent research, but unfortunately, still very much bound to small end research.