I've shot polymer on my Limited gun for years. Got my first Open gun with a steel grip. So far I like it a lot. Sure the gun is heavier and call me crazy, but are the few ounces of difference in weight really that noticeable? I would tend to doubt it. That said, the gun with a steel grip and a fully loaded big stick would be heavy shooting weak hand but I doubt that would ever be required. If the gun is balanced and feels good in the hand I think the extra few ounces of weight is more of a mental thing than a physical limitation.
Just my opinion and I admit I've never shot this gun with polymer to compare side by side. Maybe I just tend to like a little heavier gun but I plan on keeping the steel grip.