Yes it is! As far as the sound quality or playback quality of the finished copy, it will be the same as your master! CD-R and DVD-R technology has rapidly developed into a huge market over the last decade. It has brought CD duplication down to reasonable prices for short run or small quantity jobs. Before duplication, you didn’t have a choice but to usually do a minimum of 1000 discs.
The only real difference is compatibility. Duplicated discs (CD-R, DVD-R, & BD-R) are not 100% compatible with all players. A very small percentage of players (especially older players) may have trouble reading duplicated discs. It is a small trade-off for the ability to do short runs of your project.