So far, it takes a few minutes to display the thumbnails on an iPad first generation. From there, I pick and choose since I'm not using it for storage of my images, simply as a device to show people what I've shot since the camera display is too small and having a MacBook takes time to fire up and takes time to run the software, etc.
There are still advantages to downloading to a MacBook and using the better display, but for size, convenience, battery frugality, etc., the iPad is a pretty interesting device. It will display the embeded previews from my raw files, but I didn't get this to process images out in the field. Maybe one approach is to run a small jpeg file along with the raw file to more quickly download and use the photo editing software.
Now that I've got many years of digital under my belt, my plan is to see how much less stuff I really need to drag along to support shooting on the road. My overall goal is to see if I can leave the MacBook at home and use the iPad/iPhone for web/communications and image viewing, cards for primary storage, Hyperdrive for back-up and dispense with nightlight downloading and metadata, simply relying on field notes and using the desktop at my leisure back in the studio so I can shoot more, enjoy the travel more and still have time for sleep at night.
I think this is the first step and as I get more hands-on and figure out the idiosyncrasies, I'll have it all worked out. Already using an iPad over the MacBook saves in bulk, wight, chargers, and cables. I can use the same cable and charger as my iPhone and iPod, and with a USB power cable, it takes little power to keep going compared to the MacBook. Power wise, the iPad runs about 2.5 times or longer than a charge on the laptop. However, I have all the tools I need on the MBP and run my operation totally on the road. Always a trade off, but not necessarily a bad one!
As to the Hyperdrive, it downloads the images quite quickly and even though there was a glitch with trying to view/transfer my Panasonic LX-5 images to the iPad from it, the images are still downloaded and if needed, I can use the SD card reader on the iPad to grab and display.
In any case, I still have play with the new stuff and come up with a doable workflow and that will take some time.
Yes, I've considered a MB Air and the display is spectacular, as is performance and storage space for a trip, but still the issues of size/weight/battery power compared to the iPod and even a fully-decked out iPad with a Hyperdrive is still smaller, cheaper and more convenient than packing all the stuff needed for the Air.
Stay tuned for more!