Just a note on the so called "mandala" designs (made manually).
Inkscape's rendering (and all other renderers for that matter) is producing a gap between objects touching i.e. repeated/cloned objects next to eachother in a circular array. Meaning, if you wish to repeat one segment, this rendering gap is visible.
Therefore I'd suggest overlaping the tiles.
How? First lay down paths that overlap and cover the right segments, then use them to clip the tiles and make these tiles exceed the clipping area.
Needless to say it works 100% ok if there is no transparency is involved in the parent tile.
Having said that, the mentioned snowflake generator doesn't use clipping and overlapping, and would produce messed up results if the objects inside the parent group have strokes/gradient fills added.
For an overlapped "snowflake generator" check
this.
For nice examples on a basic circular array for clipping, look at
this svg.
Also a
related example.
(Although the filtering produces other rendering issues in 0.91's cairo, it works fine in chrome.)