Not much difference when using JPG
Switch the comparison to RAW and I can see that the K5II is clearer than the K5, especially at higher ISO. And the K5IIs is higher still.
A good portion of the image is the yellow angel + trumpet on the Martini bottle

Even at ISO100 there's more definition in the K5IIs.

Matt

My tip - use fully manual exposure "M", spot metering mode. Use the Green Button to grab an exposure point and work from there.

With experience you get used to grabbing a spot exposure and guestimating the lighting changes.

Personally I also switch the autofocus from half-press-shutter to the AF button on the back. That way I can use the centre point to get accurate focus lock ahead of time, and get an instant shutter release on the 'moment'

Matt

Since using Samsung Extreme cards I don't seem to have many problems at all - the cards pop out very easily

(I know that thickness of cards does vary, and it can be a real pain removing them even with the 'flick' approach that's required on the K5)

Matt

I use the image comparison feature from time to time on the K5.
Looking through the manuals it appears that Pentax have deprecated this facility - it's not in the K-30 nor in the K-5II or IIs

Shame.
Matt

FWIW, to test IR remotes, just point a cheap digital camera at it.
Most phone cameras are IR sensitive, and pressing the button should show up nice and bright in the phone image
Matt

Update:

I downloaded a few profiles to have a peek. On the Mac they are saved in ~/Library/Application Support/Adobe/CameraRaw/LensProfiles/1.0/Downloaded

The files have a ".lcp" extension.
Actually they are XML text. Just open with an editor - and you'll see the tag (e.g. 8 18 for the Sigma 8-16)

You'll probably be able to tweak a profile that matches your lens

Matt

You may find this page helpful (but complicated!)

EDIT: and here you can download the "Adobe Lens Profile Downloader" tool that will search for user-supplied body+lens profiles

LR will only apply a lens profile if the Lens ID in the EXIF matches the available profiles.

I suspect you are manually picking a Sigma lens that sounds the same but that has a different Lens ID embedded in the profile
EDIT: Or may even be the same lens. Sigma may have produced different batches of the (optically) same lens but with different ID chips.

If the profile was copied and the internal ID changed to match your '8 23' then LR should pick up the profile automatically.

Matt

Doubt it
The fact that PhotoMe shows the Lens ID correctly but not the name shows that the EXIF is intact. Are you sure you're picking the correct profile in LR? ID "8 255.1", "3 46.1", "8 16" all refer to variants of the Sigma 70-200/2.8
(See the list here)

I've even thought about creating my own lens profiles... but it seems like such a hassle! And I need a largish print out of the calibration target, along with a very big room

Matt

I have the Cactus V4 flash remote triggers which are spec'd at 30m.
Apparently you can wire them up as a remote camera release too
(Have seen it, but not tried - think there was a thread on here...)

EDIT: Here is the Flickr stream that shows how to do it with the v4... must have a go myself

The Cactus V5 are spec'd at 100m and there is an optional Pentax/Canon shutter release cable

EDIT: Cactus also do a Wireless shutter release that is dedicated - 15m.

HTH!
Matt