Yes, it's compatible. I've removed the actual link as, apart from BIN items, the general consensus here has been that putting eBay links in spoils the chance of getting a bargain. Some members object quite strongly, so best avoided.

You're missing that there is a filter to replace the AA filter, otherwise focus would be off. It's a clear filter, but obviously coated as per the original.

It's been very well documented in tests on the internet and in magazines, covering Pentax and Nikon but also many new cameras that also have no AA filter. The Pentax Q series and the Ricoh GR are two recent examples of cameras with no AA filter.

It seems to be the way things are going.

Resilvering a mirror is a highly skilled job. Perhaps a Google search for lens repairers? It a bit more than just an average repair though.

Very good, using a fisheye is not easy.

Very nice kit. It would look even better in one of those snazzy aluminium fitted cases....

Same model is fine, but same sample can be tricky, depending on when the review samples arrive. For example, the K-5 II and IIs were received at EPZ several weeks apart, so when I did the IIs report it was very difficult to remove all variables.

However, it didn't take long to establish what I wanted to know for my own future purposes.

This isn't quite the same thing. It's referring to enabling extra electronic features, which are indeed very low cost.

In the case of the K-5 II and IIs there is a physical difference. A smaller production line has to be run where the AA filter is replaced by a plain filter glass. It's no doubt the smaller run that causes the increase in price. Plus of course the promotion and distribution of what amounts to a different model.

However, the most relevant point is that it is more expensive, which is the reality of it.

Could you post some examples please?

The Pentax lens is an excellent one.

I've no experience of the Tamron, but I would say that 28mm is not particularly wide angle, being a 35mm-equivalent of 42mm, a "wide standard".

SDM failures are a thing of the distant past MyCynical. Lenses that did fail were fixed under warranty and SDM motors now seem to be very reliable.

The new 18-270mm seemed to be a suitable candidate for a DC motor, but it is actually marked up as SDM. So the DC motor lens seems at this time to be a one-off, not a conspiracy.