That depends. Are you going to be watching DVD movies on your computer? If yes, by all means go in for a DVD drive. The 166S costs Rs 2200-2500 here in Bombay. But if you are not going to watch DVDs on your computer, and are looking to burn >1 disc simultaneously, you can go in for a writer like the 8481B, which costs 3300 Rs here in Bombay. The choice is yours to make. But just remember that when burning 2 discs simultaneously, you will only be able to burn at the speed of the slower writer, but this should not be a problem in your case, as you already have an LTR48125W.
For general use, both a DVD drive and a writer would be pretty much the same (speedwise). So the choice is yours to make, after evaluating your own needs.
Good luck making up your mind
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