K-5 highlight protection question

My understanding of the K-5 highlight protection is:

Let's say you have it on and set ISO 200. The camera actually will take pic underexposed at ISO 100 and then boost it up 1 EV. In other words, the camera measures like it's in ISO 200 but take pictures with same shutter speed and aperture but with actual sensitivity of ISO 100. So effectively you have 1 extra EV of highlight to save at the expense of 1 EV of shadow.

That means you effectively don't "lose" any DR. You simply shift the DR from shadow to highlight. Considering the K-5 has only about 2 stops of highlight room and very little shadow noise, it is actually a good thing to turn highlight protection on (unless you really need ISO 80 - low shutter speed landscape, for example).

As a result, the only factors to decide whether to use the functionality is
1. Processing time. How much does it really slow down displaying of preview?
2. The need of slow shutter speed in certain situations.

Is my understanding correct? I plan to turn highlight protection on permanently, unless I'm doing slow shutter landscape work.

Does anyone know if my understanding is correct or not :

It is a completely pointless feature if you shoot RAW.

You can do all that in PP with next to no loss and you might as well be shooting at ISO80 or 100 and underexpose if you want the best DR and adjust the curves.

does it really have this stuff? I've turned it all off - I shoot RAW. Why do I need it? Unless I'm shooting at ISO6400, I have approx 0 noise in the shadows, so I can underexpose by > three whole stops and still get a decent JPG.

Case in point: this. http://www.23hq.com/23666/6588167_ff9964c18e8ae7c59b934b4bdc5eae64_large1k.jpg

It's 1/30, ISO 6400 and using an smc-m 135@f8. I exposed for the highlights - the rest got pushed and then calmed down in UFRaw. UFRaw said "+3.1" if I remember correctly...

You don't need it, shoot RAW.

Bret

I think I'd like to know as well.

I don't use raw very often, preferring not to spend hours at the computer. I try to get it right in the camera, if i can, and I'm looking to maybe move to the k5 when the price stabilizes a bit. Understanding the facilities of the k5 is important to me.

Knowing what it can do helps the decision, especially if it does things for me that saves me time and money, buying expensive software!