I've got 3 Pc's in my house, two with twin burners. Built upgrade and maintain 13 in total in ex's houses and family members.
I've used Sony, LG, Lite-On, Pioneer, NEC, and Plextors.
The only one I had repeated problems with was plextor failing about every 6 - 9 months. But plextor delivered a new drive the next day on reporting it with new warranty from delivery date, something they did twice more after that. So poor drive but excellent service.
The others are really much the same, although the Lite-on is noisiest and NEC generally queitest (with one NEC exception which sounded like a helicopter taking off and deemed not faulty by NEC when sent back, but they did refund my money after further complaint. But it put me off them) Sony seemed to have the shortest shelf life but that was still 2 years plus, but life expectancy is determined by number of burns rather than time served and it got some hamer.
Speed wise varies with the media used playing a big factor. Especially with DVD's. If you visit their home sites they normally list recommended media to use for specific drives for optimum performance and speed. Some media sites list the registed compatable drives for the media on sale, like svp. An example my LG 16x drive will burn a full DVD in 4.56mins to make an image from source and 3.57mins to burn the copy using Ri Disc Xtreme 16x Silver printables and Nero 7. Same source but using DataRite Titanium 16x white printables takes 7.24mins to burn the copy of the same disc.
Some media and copying forums also have custom fireware for set drives to increase compatability and speed. Though very effective especially at getting 8x discs to burn at 16x speeds, using a custom fireware voids your drives warranty
Down loading latest firmware often increases your drives compatability list with various media and sometimes ups you performance time on existing media. So always worth checking and updating every few months whatever your drive.
For overall media compatability NEC and LG seem to cover more media options than their rivals, but sony has a decent compatability ratio.
lastly burning on the fly. Source drive plays a major factor. For one you won't burn on the fly at 16x speed with a 16x speed burner if the source ROM drive is a couple of years old and has a maximum speed read of only 8x. (A very common fault) And daft as it sounds same make does not always ensure maximum drive compatability. I initially purchased an LG DVD ROM drive to compliment my LG DVD RW RAM drive, but had poor on the fly performance. It was taking 24 minutes on the fly, (thats direct reader to writer without an image being made to PC first) Where as it was actually quicker to use it to copy image to PC first, taking an overal copy time of about 8.5 to 9 minutes. I swapped it for my SONY DVD RW, using that as the source and performance increased drastically to an on the fly performance of about 5.25minutes.
Basically all good. Some quieter than others, and look at media compatability for the drive you consider buying.