From what I have seen it is very accurate, but a bit slow, if I had a suggestion, and maybe I have missed it, i would want a "range card" feature to let you display a complete range card and then you can just scroll down for longer ranges, otherwise you have to input each range you shoot and it's not very fast.
But the engine is definitely solid ... that is just an initial, I am working on it thought
I've been running a Gen 2 Eagle for about a month now - impressive, though I think it still has room to grow and there are few kinks to work out. For use with a switch-barrel rifle it's got a handy feature that lets you log the POI offset for each barrel, though this currently only affects elevation and can't handle negative values. The word I got back from Rianov is that they're looking into making it elevation/windage offsets with positive and negative values. The remote is a bit bulky and I'd much prefer a wireless solution with a toggle that can be worn like a ring on your finger (a la headset PTT), but since the CR123 battery is stored in the remote, that's probably the main reason for the bulk.
Overall the firing solutions have been pretty accurate - I tested it with my long 6.5x47L barrel and short .338LM so far and like any ballistic computer, it's all about inputing good data. The truing feature is nice too, allowing you to add actual drops over distance and it'll recompute the curve to match. Overall I'm impressed, but I still need to run it through its paces more, however I've got a Hobbit to deal with that's taking up 80 hours a week of my time.