A few questions have been raised regarding price and features.
For those with background in programming, you can probably appreciate the complexity of coding in pure assembly on a modern 32bit MCU (2500 lines of code and more to come), add in the many layers of the USB 2.0 Protocol from the Hardware Endpoint interfacing, Descriptor generation and handling, Enumeration, Mass Storage Class layer, SCSI transparent command layer, FAT file handling layer, the GB interface controller and gluing it all together is a rather complex kernel in charge of managing the many current different cart protocols.
Then add debugging hardware and software for USB 2.0, VID and PID registration.
There is a reason this has not been done in the past, that is the many hundreds of hours of coding and debugging and the price for the development boards, USB debugging hardware etc...
That being said, My prices have always been, and will continue to be reasonable. I plan on a final price lower than that of the current high end alternative. I've also invested in a 3d printer to make some enclosures both protective and aesthetic. (I'm currently thinking of an oversize cart where you insert your standard cart into the end of it?)
Onto the features,
As I said earlier, this device allows simple drag and drop of ROM's and Save's to and from a Flash Cart. If your cart supports multiple ROM's on the one cart, you will need to generate your compilations in the same way as you have before. Be it EMS, Bung, BennVenn. It is these files you drag onto the cart, or simply drag a stand alone ROM without menu and that is fine too.
I'll be adding a simple menu generator to the firmware for my BennVenn carts, dividing the cart into 4 regions and allowing individual transfer for each region. This won't let you store hundreds of ROM's like my compiler software does but simplifies things a whole lot for those that don't want to deal with a compiler program.
My first gen Reader/Writers and Linkers (and soon the Gen2 products) will still be available through Ninstrument.Com for those after a budget cart tool - and to be honest, there are still more features built into the Flashtool program than is possible using just USB Mass Storage implementation (On the fly register modification, bank switching, selective erase and writing etc...)
If you want speed and simplicity then I'd recommend the Gen2, If you want to dump some exotic cart with a boot menu, you will need the added features of the Gen1 to manually ROM swap via software to extract the ROM's.
-Ben