We are in the middle of trying to decide between iWay adapters and Oracle Fusion Middleware. We want to write to JDE 8.9 real time from our custom POS system. Have you looked at Fusion Middleware at all.
I am not an IWAY person, so I can't tell you much about it.
AFAIK there are no major issues with it in our configuration (we are on 8.11SP1 , AIX 5.3 / Oracle 9.2.0.6)
Yes, we did some tools release upgrades. I guess 8.94 something was the original ones.