I have listened to unabridged versions of Northanger Abbey, Sense & Sensibility, Pride & Prejudice and Emma. As well as abridged versions of Persuasion, Mansfield Park, Northanger Abbey, Sense & Sensibility, Pride & Prejudice and Emma too. Of all the audio books, abridged and/or unabridged, Austen's work is the most of what I've heard. In other words, I've listened to her works more than anyone elses.
The first time I ever heard an unbridgement of an audio book was Pride & Prejudice. I had already heard one or more abridgements of this story (I can't recall) and this was the first time I was trying the unabridgement. Certain things that were left out in the short version while others were left in the same version made more sense in the long version. The story had better continuity in the full version as oppose to the cut version. Which resulted in a better story. I prefer unabridgements to abridgements because one gets more of the full story than the shorten versions give. More of the world that these characters live in. More of everything. As for the readings of these audio versions it doesn't make a differnce if the reader is reading the shortend version or the full one in terms of performance. At least in my opinion. Generally I don't listen to an abridged version of a story when I've already heard the unabridged one. I tried it in the past and I find myself thinking that the abridgement is missing something and that undermines my ability to enjoy it. I first tried it with an abridgement of Pride & Prejuduce and I found it frustrating because of the missing details that the unabridge had. It's better listening to the full version than the short one after hearing the unabridged version. The only way that listening to the short version after hearing the full version isn't frustrating is when the short version is better than the unabridged one. But I've yet to have a situation where that has happend.