I have the GWPanther as well as the gwtiger. I prefer the panther though the crew on the tiger is not up to par yet. I think I have gunner/commander at 100, loader at 90 and others creeping up from 75.
30+ second reloads hurt when damage is minimal.
as mentioned, without a decent team arty is wide open to a quick death. The Panther has a little speed on it, the Tiger just lumbers along waiting for a t50 to shoot its ass.
with the latest update the arty mod no longer works. i miss the time to target calculator.