I don't have either of these drives... the closest I have is the DVR-212D (SATA version of the 112D)... It is a good reader/writer, the 212D won't set the booktype of DVD+R to DVD-ROM, but there is Buffalo firmware available for the DVR-112D to allow that (using it voids your warranty).
Overall, I like LG drives and have a couple of them (GSA-H22N and GSA-H62N), but what I don't like about them is RIPLOCK and a lack of firmware development. Instead they just release a new model. Additionally, from what I read about the GSA-H55N, it incorporates a new technology for disc encryption called SecurDisc. I am certainly not impressed with the technology because it seems to be proprietary with newer LG drives (so far only the H55x series/Panasonic chipset) and only works with Nero. I don't see that making an impact. If I am going to secure data, I am going to use TruCrypt or OpenPGP (Gnu Privacy Guard).
Based on your choices, I'd say, advantage Pioneer.