Simply put, QA is very important. Quality Assurance testing or in certain lingo is defined as UAT or User Acceptance Testing is employed to reduce possible defects in every stage of the software development life cycle.
The focus of Software Quality Assurance is to monitor continuously throughout the Software Development Life Cycle to ensure the quality of the delivered products. This requires monitoring both the processes and the products. In process assurance, SQA provides management with objective feedback regarding compliance to approved plans, procedures, standards, and analyses. It focuses on the changing level of product quality within each phase of the life cycle, such as the requirements, design, code, and test plan. The objective is to identify and eliminate defects throughout the life cycle as early as possible, thus reducing test and maintenance costs.”
The main goals of QA during software development are to develop error free software, to determine if there is any variation from software requirements, to use the software in a real time environment, and to provide confidence in the software, among other things. The bottom line seems to be that QA is important, and that customers would prefer to wait slightly longer for a quality product then receive a potentially flawed one sooner. You are better off taking the time to complete it than not.