Squidy....yes, I've used it w/my grad filter, w/my Big Stopper and in combination of these 2 filters. Don't be afraid to test the extremes of your equipment....play w/your new tools and learn what they can and cannot do.

By playing w/your "toys"....it also allows you to become familiar w/the tool and allows you to build confidence in using it.....while having fun.

I played w/a number of my pix w/LR's grad filter before I became comfortable using it.

Here are some LR grad filter examples at Flickr (specifically the 3 Revolutionary pix); http://www.flickr.com/photos/29409592@N03/

These were taken midday w/a CP attached.

Enjoy your new toys Squidy

Bill