First of all, I love Lightroom. However, when you export a file 100% quality jpeg with and without the external hard drive attached you get completely different results. With the hard drive attached you get a larger file size then without the hard drive. Since many of us have so many photos........and the file sizes are so very large....we are very happy to be able to work "off line" without having to be physically connected to the external drive. However, I found it very surprising that the final output.........is not the same when connected vs. not connected. Thanks so much!