Even too much Java has caused crashing, which is a quick way to create a negative impression from the visitor. (Remember when LookSmart’s site was “very” Java. It was like watching snails race . . . Getting nowhere slowly.)
The key to having a chance in succeeding with a commercial site is how well you present what is being offered by description, features, and benefits. This means content! The site’s design / presentation needs to revolve around these elements.
One particular good use of “glitz” is with offering specials and other incentives to attract immediate purchase and revisits. However, it should not be overdone and should lead the target audience to more detailed information.
Never forget that well-written content is required to develop perceived value. Glitz should reinforce it. Oh, yeah pictures of products and testimonials of services used can only help if done right.