K-5 DR question

[blackcloudbrew]

This may not only be for the K-5 but also may be for the K-7 as I don't own one and don't know if the K-7 has the same menus as the K-5, however...my question is this. On my K-20 when adjusting ISO, you can set the dynamic range (DR) to an increased value that, AFAIK, changes the minimum ISO from 100 to 200 and works to increase(?)/modify the DR in shadows and highlights. I've gotten very used to my K-20's ability to do this in strong contrast situations. My brand new K-5 (ok, I'm only half way through the manual), apparently has no exactly similar feature to affect the DR but it does have two items that do, I believe, essentially the same thing - highlight and shadow correction. Highlight correction clearly bumps the minimum ISO up x2 just like the K-20, while shadow correction does other things.

Assuming that the K-5 features are the same DR expansion deal with more control as the K-20, what I'd like to ask for those of you K-5 (or K-7) users what your operational experience is with these controls. Do you have a rule of thumb when to use it, how to use it, experience with it you'd like to share. Or is it one of those bells and whistles that you don't bother with? I note that the Pentax image development software has the same options to apply to the raw images so clearly it can be done in PP too. I'd just like to know if others use it or find it useful or what. I did a big shoot yesterday and as I've only had my K-5 for 4 days, I was fumbling with the menus/controls.

[calsan]

With the K-7, I have the highlight correction left permanently ON (ie minimum iso now 200). 
The reason for this, is that it's really easy to get overexposed areas which, unlike underexposure, can't be recovered in PP.
I leave the shadow correction OFF: I find it makes photos look "flatter", which I don't like.

[blackcloudbrew]

I haven't seen any results with the highlight correction that I can define but I have seen that the shadow correction does seem to flatten the contrast. Thanks.

Any others with input on this?

[tcom]

I have not used these functions, neither on K20 nor K-7 as I found that they do increase the noise in the shadows.

On the K-5, I have not even tried these. I do shoot RAW, and Lightroom does a pretty nice job with the fill light to lighten up the shadows, and this is where the K-5 really shines, on the K-7, when applying fill light, noise appears quickly, but no on the K-5. You can greatly light up the shadows without increasing the noise.