Darktable -- best possible experience -- how?

[PeGa!]

Hi folks,

After a long hiatus (mostly for time and work reasons) I'm back on Gentoo and my gentoo-fu is a bit rusty. I'll be doing a series of posts in order to regain my familiarity with Gentoo, starting with this one:

How to get the best of Darktable with Gentoo USE flags?

I don't want to blindly enable all available USE flags, I just want a smooth usability without interruptions. For example, last time I used Darktable in Gentoo, I ended with some red boxes here and there in the main interface -- something that didn't happen with other distributions. While now it works pretty well, I'd like to anticipate to any possible pitfall I could have ahead of me. (I should have stated by now that, as an photography enthusiast and a IT architect focused on *NIX, I prefer Darktable to Lightroom.)

Enough chit-chat, straight to the point:

First of all, I've got a working Plasma desktop with some minor annoyances (more on that later) on a Core I5 generic ultrabook.

Info about my device:

emerge --info | lspci | usb-devices

How I've got my Darktable right now:

[fedeliallalinea]

Usually default use flags are a good starting point and rarely I need to enable somethings else.
Enable and disable use flags is a personal decision and you can check detail with euse -i <use_flag_name> command