I started listening to audiobooks a couple of years ago, through the admirable Audible company. I mostly listen to the books while cycling home, which makes it difficult to skip back a few seconds when my concentration slips and I miss a bit. I soon realised that this mode of reading is more suitable for fiction than non-fiction. The mind-blowing 'Decoding Reality' really deserves a re-listen in less distracting circumstances, while '50 Philosophy Ideas You Really Need to Know' I gave up around number 15, after a near miss turning onto Haxby Road while using rather less of my brain than I really ought to have.
For stories though, it's ideal, and I'm using it to catch up on authors I might otherwise never have found the time for, or getting through the complete works of Stieg Larsson (sadly only three).
I had one worry though: is listening to a novel rather than reading it cheating?
Recently I was sat down with a real book, 'Use of Weapons' by Iain M. Banks. It's one of his Culture novels (masterpieces of SF, if you've never tried them), and I stopped to count the ones I'd already read. I knew there were three, and that one of them was an audiobook. The interesting thing was that I couldn't remember which of the three was the one I'd listened to. As far as my memory was concerned, I had the internal 'soundtracks' of three novels, and I couldn't tell the difference in quality between the one I'd heard through my earphones and the ones I'd made up myself as I read the written words.
So as far as I'm concerned, the answer is 'No: audiobooks are not cheating'. At least, it isn't for me. The end result in my memory seems to be exactly the same, except that I can now combine some of the more tedious parts of my life with probably my favourite hobby.