Is there any reason to use non-standard buttons in the installer? It looks hideous to me and it is impossible to tell which control is currently active which makes keyboard a game of "guess the tab-order".

I'm guessing just to keep it in line with the rest of the GOG.com branding, which I imagine they're trying to push pretty hard at the moment.
Another question you might want to ask yourself is "Is there any reason to change them to 'standard' buttons except for that one guy who thinks it's ugly and doesn't want to use his mouse?"

I actually like that the installer is different than your usual InstallShield style wizard. For the first time in a long time, I actually paid attention to every step of the installer, rather than almost robotically clicking next, next, next, install, ok, as the standard Windows installer has conditioned me to do.
My only complaint is that for some reason, every time I launch an install, the installer opens up partially off the screen in the lower left of my desktop. However, I'm sure that is actually something on my end and not a problem with the installer itself.

having a different installer, to me, says that they are quality, and further backs their claims in my opinion, that they are indeed a legit company.
Although, I've known this for a long time, I think it can help for some of those newer customers.
but it's in line with the branding, yes. I also like the pretty pictures..

I like the big DRM FREE picture during installation : ).
And I have no problem with using my mouse, and therefore with using their installer.

Who cares what it looks like or how it is used or the control scheme behind it, as long as it works as intended.

I wasn't trying to write him off. I was just stating in a roundabout way that the installer worked for me and I did not see any problem with it.

I should get a new pair of pants, every time I have to use the installer for a GOG.com product.
it's the principle of the matter.

I actually do have a display issue with the installer: some of the elements are jumbled, overlapping, or cut off by the edge of the window. I'm wondering if that might be my 120 dpi Windows font size.

No elements are jumbled, overlapping or cut off on my end.
So yeah, it probably has something to do with your settings.

I think your spot on with that one.
The only "issue" I've had is the window cutting off at the bottom right of my screen, but with the 0.2 sec. that it takes to centre the window it's no big deal.
I think the installer goes well with this site. We don't really want everything to be the same do we? The site is openly trying to accomplish something a little different. So why shouldn't its interface reflect that?

I love installing GOG games because of the installer. The style is fantastic, and the way it breaks away from standard windows is very appealing. The buttons are fun to click. It's really the greatest.

I can't tell if you're being serious or not...

Serious. It's one of my favorite things about this site - the simplicity. We can all do what we need to in order to get these games running, but it's such a pain compared to the GOG installer.