It's definitely a cool product, but I don't really know how neccessary it is anymore.
Desktop A1200s only have a finite level of hardware expandability, meaning that there's only a finite amount of stuff that can go in the startup-sequence that requires a reboot. For 1.3 compatability, WHDLoad is far more convenient than running stuff "natively" through Relokick, or something. I can't think of any 1.3-only productivity apps that aren't completely obsolete by now.
I'd say that nearly all Towered A1200s have some form of Zorro expansion, meaning that the same results of the Kickflash can be achieved through an Algor, KickflashOS4, or eFlash. The Algor offers more functionality (being a USB board and all) for only a little more money, and the other 2 boards are significantly cheaper than these flashable Kickstart ROMs would be.
The same applies to other big box Amigas.
The A500 already has a FlashROM board - though you've got you build it yourself. Plans are on Aminet.
The A600 is too difficult to expand to make any sort of ROM switching neccessary.
That's my opinion, at least.
