Its not the drives that need improving, its the media. Most 16x media doesn’t ever reach its rated speed, as well as that, it usually has bad read speeds towards the edge of the disc. Only expensive TY media burns reliably at 16x. I’ve not seen a reasnably priced DVD-+R that burns at 16x on a regular basis. Even now, 8x is where its at, and even then, you’ll get dodgy spindles of average priced discs with every 1 in 5 discs or so not reading correctly towards the end of the disc. A 16x burnt disc should finish in under 5 minutes if its really burning at 16x CLV. You will find that a full disc actually takes 5:30-6:00. Just proves that 18x burning will just mess things up even more.