I'm using a Reyee RG E5 - similar hardware to RT3200, but with external antennas and not much flash. Available open box or used on ebay for decently under $50 lately.
The Reyee has much better intermediate to long range 802.11 ax 5GHz throughput than the RT3200 did (~500 Mbps vs only ~300 Mbps with RT3200 in same AP and client locations). The Reyee also can be set up to U.S. txpower limits on lower and upper 5GHz channels (30 dBm), whereas the RT3200 is stuck at 23 dBm on channel 36 and 27 dBm on Channel 149, which is less than ideal if running more than one RT3200 in a mesh setup.
But no third radio, and as noted, the 16MB flash is tight - limiting for a gateway perhaps, but fine for just an AP. The Reyee also runs a bit hotter than the RT3200 did (~59C versus ~53C for the RT3200); however that is probably irrelevant being within operating range either way. I've thought about adding a 1 inch hole top center for better airflow, but probably won't bother.