I’ll first write the text, and will include the pictures afterwards.
If you thought you could use those discs in older drives, forget it: The Pioneer DVR-A09 only supports them at 2.4x, and the write quality is nothing to boast with.
NEC NEC ND-3540A supports them at 8x, but the result is suboptimal when scanned with a PX-716A, and simply sucks when scanned with a PX-712. The bad thing is, the PX-712 has not been “designed” to read DVD+R DL and probably resembles the behaviour of a lot of older players not specially designed to read them either.
The LG 4120B does not support recording them
The PX-716A is showing a very good result at 6x speed, however, it is not better than the result with normal (not printable) 2.4x media, so there is actually not really a point in using them, unless the price is the same.