When it comes to hardware I'm no expert, but anyone armed with a screwdriver can replace or upgrade their existing internal DVD drive.
I ordered the cables too just to be sure (they were only approx £1), although I didn't actually need them in the end - the drive just plugged straight in using the existing cable.
Windows xp recognised the new drive straight away, and within minutes of opening the parcel from Amazon, I was burning new disks. I didn't even need to find a driver. I wasn't bothered about writing speed, buffering whatever, I just wanted something cheap, easy to install that works - this unit ticks all the boxes and was about half the price of the basic models I saw instore.
Update Aug 2011. The drive recently developed a problem; the audio on any DVD that I play is now stuttered and jumpy. Have tried several DVDs and the result is the same. If I try them in another DVD drive it works fine, hence problem with this unit. I emailed the suppliers this week but they said that the warranty is only for a year and I have had it 14 months. Unlucky. Also they no longer stock this item and recommended I buy a SATA drive instead. Which I just did for £15.