well, I've never regretted opening anything (even my Toy Fair Vader, althought I do have one still carded also) To me looking at a carded figure online is about the same as looking at a carded figure in your hands, it looks exactly the same, and peoples carded displays look less like a collection and more like a Toys R Us aisle.
With loose figures you can move them around into different poses, display them a variety of ways, display them together, literally "experience" it as a toy like it was meant to be. Kind of like owning a book with a nice cover, it looks nice but you don't get the full enjoyment until you've read it. I still have some carded (Vaders & Yodas) so I can appreciate the art and design, and progression thereof. (except the design of the TAC figures....good lord I hope Hasbro doesn't hire on as a full time designer the sophomore intern from the local community college that designed those atrocities ....)
-Dan, a reformed carded collector