I think the virtual museums are comparable to physical museums because it contains pieces of art and detail to go along with it. Virtual museums are better in my opinion because database archival and hypertext links make it easier for me to find information and details of the piece of art. I like this better than the catalog in real museums and it is a lot quicker than catalogs.
I don't feel that there are any problems with using a virtual museum. The only thing lacking using virtual museums over physical ones is seeing the actual art in its original form. You can not witness brush strokes, technique, or true detail online.
Virtual museum exhibitions allow you to look at mass amounts of artwork from different museums without leaving your home. You can look up information and details with just one click and results are fast and easy. You do not have to limit yourself too looking at one piece at a time or one style or artist. Not only can you look but you can create your own gallery of your favorite pieces.