I have seen a lot gripes and complaints about the 1/180s "flash" x-sync speed of the K-7 these two days.
As a professional electronics engineer who has been working in the industry and relevant fields for decades myself, I have something to say for the Pentax's engineers.
The possible major constraint of the K-7 is the miniature size.
X-sync actually represents the highest speed which the shutter blades, i.e., front or rear curtain, is capable of moving.
The 1/8000th is not the true speed of shutter blade movement, it is just a narrowed gap as "line scanned" when the maximum x-sync is exceeded. So, its easy to achieve even with the "existing" shutter.
To make faster shutter blade movement, more instantaneous *power* (energy over time) is required to actuate the shutter and/or lighter shutter blades are required. I believe the materials for shutter blades have been already well established years ago. There is minimum thickness and hence mass of the shutter blades as they have to be strong enough.
So, to make more power to the shutter movement, more powerful magnetic force is desired. So, the magnetic coil need to make larger, with more turns of coil as well as thicker wire for more/larger current -
so as to provide the very high energy within a very short period of time. As a result, such the shutter will be (much) larger, as it is required (and consume more battery power as well).
Afterall, I think technology is not a barrier for Pentax to include a faster shutter. As they purchase from Copal anyway. But, the size is, which I believe is the major constraint.
As long as Pentax have to choose between smaller miniature sized
DSLR or a higher X-sync, they have NO CHOICE!