I've got different experience regarding Genesis, AmiTCP, EasyNet.
I had been struggling hard setting up any of them. Every time I had tried there seemed to be some problems.
On the other hand I've never had any problems with Miami, MiamiDX or my favourite TCP/IP stack, RoadShow. With RoadShow I've had no problems at all on any of my Amigas, starting from A500+ with Plipbox, A600 LAN&WLAN, A1200 LAN&WLAN ending on A4000 with Ariandne II and MorphOS 1.4.5