In general, any operations with USB 2.0 will be slower, right? I used to use the "make duplicate copy" when importing images but found it slowed the process down to much. My workflow now, while on the road:
1. I create a Catalog for the trip (like I just did Europe2013).
2. Import images as I take them (like each night). I keyword, possibly rank, delete some clunkers, etc.
3. At night/while out to dinner/etc, use SyncToy (
http://download.cnet.com/SyncToy/3000-2248_4-10629009.html) to replicate the images and catalog to my backup SSD. I keep this backup SSD in my wife's luggage (i.e. spreading out my images among our luggage). Note that with this method, changes I might be making to my "travel catalog" during the trip are continually applied to my backup.
4. When I get home, I import from the SSD into my MAIN Catalog on my desktop.
5. Once all is set and I'm sure I have all my images on my "main" desktop, backed up to my various places, I delete the "travel catalog/images" from my travel laptop.
This has been refined over many trips and is the fewest number of steps, whilst continually having 3 sets of all my images during my travels (because I don't overwrite my SD cards and I keep those on my person).
Hope it helps! Bob.