I have several 4X and 8X recorders, but ever since the days of Pioneer 103 I've been sort of partial towards the Pioneers. I had a very well functioning 106 for a while, but then made a mistake and sold it to make room for a 107D.
Now, 107D is one nasty beast. By this I mean its firmwares and how darn picky they are. Let me explain.
I use three different brands of media. If I want to store something important, something I want to be able to read off the disc after 4-5 years, I use Verbatim DataLifePlus (MCC). If the data is not that important, I go for RiDisc (Ritek G04 Grade-A).
Recently I bought a bunch of Platinum-brand 8X-certified discs that turned out to be manufactured by CMC Magnetics in Taiwan (though they were supposed to be RICOHJPN02 - I won't shop in that webstore again). They should be perfect for data I just want off the HD quickly; for data I won't mourn about if the disc becomes unreadable in a year.
For MCC, the best results come with firmware 1.09. It burns Ritek pretty good too - but it sucks with CMC. v1.12 did a lot better with CMC, and 1.13 even more so... but both suck with MCC -R and +R.
Looks to me like every firmware since 1.09 has been geared towards producing good quality on cheap media, on the expense of the more expensive and reliable media. I'm quite certain that when the cheaper media starts producing read errors in a couple of years time, Verbatim, Ricoh and Taiyo Yuden will still produce error-free reads.
I want to be able to store data on any media I have on hand, reliably and quickly, without having to worry about whether I have the right firmware for the job installed in the drive.
Having now tested many different firmwares with a variety of media on the 107D, I'm at the point where I can't really trust any of the burns anymore.
That means I need to check each burn with KProbe and Nero DVD-Speed... and what's the point of a 8X burner, if I have to spend another 15 minutes checking the disc afterwards to see whether the data got burned properly.