Quite an is a phrase that is commonly used to describe something that is significant or remarkable. However, there are many other alternatives that can be used in place of quite an to add variation and interest to your writing. Some synonyms for quite an include rather impressive, truly remarkable, exceptionally notable, undeniably noteworthy, and exceedingly notable. Other possible alternatives include astonishingly remarkable, incredibly impressive, remarkably noteworthy, and truly exceptional. By using different synonyms for quite an, you can add depth and complexity to your writing, making your text more engaging and memorable to your readers.