I've been using my Pioneer DVD-115 since my last DVD-ROM drive from Sony died out on me a few months ago. If you want to read more about that story, please check out the following link:
http://www.epinions.com/content_26572656260/tk_~CB008.1.13
With that said, let me start off my review of DVD-115, starting with installation proceedure. If you have installed an internal CD-ROM drive before, this ain't much different from that. Only thing different from standard CD-ROM installation is to assign a region code for your new DVD-ROM drive, which is very simple & easy to do. If you are new to the whole 'DVD region code' business, just beware that you can change your region code for your drive only a small number of times (usually 5 times without getting the manufacturer involved). But if you don't buy any DVD movies overseas, you wouldn't need to worry about this though.
As far as DVD movie playback, I thought x5 speed drive was adequate. However, DVD-115's blazing x16 speed certainly doesn't hurt. Especially on a double layered DVD, the transition from one layer to the next seems to be a bit smoother with shorter pause time. Unlike many DVD-ROM drives currently in the market, DVD-115 can actually replace your CD-ROM drive with its more than sufficient x40 CD read speed. Even at such high speed operation for both DVD & CD, the drive remains very quiet and error-free. According to Pioneer, the drive is equipped with a special disc stabilizing mechanism that helps with quiet operation & reading discs that normally would not work on other drives. Well, I can certainly testify to that. DVD-115 has read many of my old scratched CDs and CD-ROM titles that did not work on other CD-ROM drives.
The front panel is clean & simple. There is a small LED to indicate the drive status next to eject button. There is no 1/8" headphone jack or volume control, which I always found quite useless anyway. On the tray-loading model (as supposed to a bit cooler looking slot-loading model) the disc tray can be manually opened if a disc gets stuck. If I were to be really picky, I do wish that the drive had another LED to indicate the disc type (DVD or CD), but that is a very minor issue.
I use my DVD-115 through Hollywood+ decoder card, Diamond Viper V770 Ultra, and Sony G500 21" monitor, and the picture quality from DVD movies is phenomenal. I don't have a surround system on my sound card but the sound quality is still very good. I'm sure if your sound card has 5.1 Dolby Digital decoder (such as Sound Blaster Live! Platinum 5.1), you'll be able to enjoy the DVD movies in their full glory!