Well, as a Linux user, I certainly don't have Krita take anywhere near as long as you posted above. Sounds like a platform specific issue...

It is a bug speecific to freebsd, I even have identified the problem, for some reasons it is loaded almost all the library again and again for each plugin. It is most likely a KDE wide issue (might even be Qt wide). But most likely the impact is mostly visible on Krita, since Krita has a load of plugins, and possibely some library has a heavy impact on loading. Unfortunately, FreeBSD lack(ed) good profiling tool, which is basically one of the reason I stopped trying to use it, so I was unable to track exactly where the problem lies. (if my memory serves me well, the library with the most significant impact is kotext)

I find Krita very useful! It's easily topped Photoshop, it's brushes are more complex then SAI, and it even has the feel of Manga Studio with the way it has presets for comic panels. Then there's certain things I notice only Krita doing, like the reference docker. It's very easy to use and I've found that it only lags on computers with low RAM, but that could be said for most graphics programs. That and my Monoprice tablet has amazing sensitivity in Krita, whereas it only had this sensitivity in SAI, and SAI doesn't have the brush engine that Krita does.

The only thing I don't like about Krita is the lack of a navigator, but then again, I found I don't need one. Krita has been the most amazing tool I've used, and so I have to conclude that it's easily very useful to me. c:

Well, a navigator panel is on the todo list: https://bugs.kde.org/show_bug.cgi?id=329959