What's new in it?
I saw my Die by the Sword box in my closet yester and I thought i'd play it, but I remembered that GOG.com had a version of it as well, bundled with the addon I don't have myself.
What kind of additions does the addon add? I'm mainly in it for the singleplay campaign, so if there's anything new to the singleplay, I probably should buy the GOG.com version.
Also, does the GOG.com version have an updated executable that works better with XP/Vista etc?

As far as i can tell they did some magic with it and now it should work without problems; what they exactly did, i don't know.
limb from Limba adds a pretty long and nice "campaign", there's not much story involved, actually nothing at all, other than kill everything, but if you enjoyed the gameplay of the original you'll like this one too.
they also added some monsters/weapons to the arena but not really that much.
if i had the choice i would buy the GOG version.

You mean you don't? :P
Thanks.
I wonder how's the joypad support, it would be cool if you could map player movement to PlayStation style joystick's left stick and the sword to the right.
I'll probably need to buy something like Pinnacle Game Profiler for that though.

Since i already made my choice, and buoght it on GOG, i don't have any choice anymore XD
now that you mention it i wonder if you could use the Xbox360 controller with this game, even if actually i find the mouse+keyboard vsim decent enough.