1.The NEC 3520 has better quality burns with the media I have tested (see sig) than the Pioneer 109. That would be my first choice.
The 109 has significant reductions in the total PIE/PIF errors as well as the max level of errors.
The LG also has better scans than the Pioneer and it reads and writes RAM.
If you look at the scans and media scores in my sig., you can see the data I am relying on. If you don't want to wait for the later versions of RAM drives, the Pioneer 110 and the NEC 4550, the LG would be the best all round choice with the following exceptions:
The LG is a very slow ripper and no hacked firmware seems to solve this problem.
The LG will not scan.
The LG will not bitset +RW media.
Keep in mind, the Pioneer will not do any bitsetting and I have not seen what it will do for scanning. It is a very good ripper and I use mine for that primarily.
It is hard to just own one drive. You need to balance cost, availability, features and burn quality. I rank burn quality first. I add additional drives for features.