Grips were included for free with pre-orders.

Who's a pretty boy then?

Shop demo model perhaps? Customer return under distance selling regs?
Its guaranteed so if you're thinking about it go for it!

Thanks, but as I said, uninstalled now. Don't feel it adds anything I can't do already other than add to hard disk use! Don't feel I should be having to fiddle sourcing plug-ins for industry standard dng files. Just the typical way Corel go about things, as bad, if not worse than Adobe. Programs they've wrecked include Family Tree Maker, Roxio's Go Back and I think this AS3 used to be called something else when it was probably quite good.
I was wondering if the issue was this isn't the 'Pro' version and just a trial hence lack of raw support.

Its not difficult to experiment with old lenses. One can buy and try and if not happy move them on for more or less what one paid. It's possible to build a good collection of excellent primes such as many of the Pentax K & M lenses for comparatively little money.

Thanks, worth a try. I've just installed it and it doesn't seem to see my K-1 dng's, only jpegs. Seems a similar problem as reported here:
https://www.pentaxforums.com/forums/32-digital-processing-software-printing/3286...
For whatever reason, by the time you've read this I'll have uninstalled it! Doesn't seem to offer anything I can't do already with Elements and Irfanview, probably less if it can't cope with dng's. Being Corel I didn't have high hopes given their reputation for bloatware. They have history for making simple things too complex for themselves.
By the way, at no time was I requested to enter the registration code.

Same applies to new lenses too! Clearly a budget lens that cost £10-£20 brand new back in the 70's (eg the early zooms) isn't going to hold up as well as a good quality item, but it doesn#t mean it wouldn't be worth trying. I tend to find flare is the biggest problem with older lenses, especially where dust has got on the inside of the front element. Having recently dismantled and cleaned an old Tamron 28-200 recently, the improvement after cleaning was remarkable.
If the corners are naturally out of focus it doesn't really matter if the lens can't resolve them. In the end, you get what you pay for but the differences can be marginal.
As to the OP's query about the Sigma 24-70, can't comment on that one but the older Sigma 24-60 f2.8 isn't too bad at all and minute in comparison to the 24-70's.

Just look at all the wonderful photos taken with a K-1and old film lenses on here and elsewhere. They speak for themselves.
Despite some thinking otherwise, full frame doesn't push the lens so much as APS-C so an old lens that seemed deficient on APS-C may be just fine on FF. Pixel peep, though, and the deficiencies may again become noticeable.

Try one of these:
http://www.ebay.co.uk/itm/ASTRON-SUPER-WIDER-SEMI-FISH-EYE-LENS-58MM-SER-VII/132...
Budget fish-adapter which screws in front of a standard lens. I've had one for ages. Oddly it is possible to see the lettering around the edge of the adapter so I painted over it.
There is Youtube video, albeit a poor one IMHO (due to poor taste and presentation of unnecessary distorted 'music') that shows it in use:
https://www.youtube.com/watch?v=zeiFBGV5zWI
It's a cheap way to find if a real fish-eye lens is right for you.

As for a real fish-eye there's the Samyang 12mm
http://www.northlight-images.co.uk/samyang-12mm-fisheye-lens-review/
It's pretty sharp at the edges and in the corners.

It begs the question, was the K-50 nothing more than a firmware update to the K-30 by Pentax?