System 6000 users have come to expect substantial yet free upgrades time after time. The MKII, however, involves so much new hardware and software that another free ride wasn't an option.
On the other hand, users are not forced to upgrade. In fact, software version 5 is released free of charge to original frames. Users of the original machine will therefore get some of the benefits we have put 6 man-years of effort into, while getting the MKII ready.
This is a brief description of the changes from MKI to MKII:
The floppy drive was becoming a problem in several ways. Most importantly, the software couldn't grow any further, thereby preventing new FPGA co-processing functions from being implemented along with support of new cards and algorithms. Host processing hardware changes were needed for bank store/retrieve functionality, connection to the TC site for software downloads, wi-fi functions etc. On the UI side, the LM5D radar meter was crippled by the slow performance of the MKI CPU. And with the latest Apple gadgets, users had come to expect faster a response from a touch device.
The bottom line is that we had outgrown the MKI, while the MKII provides a host of new possibilities.
Even without making promises for the future, an upgrade should make sense, but it's entirely up to the user. One option is to wait with a decision, before the next sw release (after v. 5) -- which will require a MKII -- is released.