I use both the current professional as well as the community version in Linux. I have a few issues with this otherwise very smooth and intuitive program:
1. Line widths:
I sometimes draw stuff at the sub-mm scale, at which point the standard line thicknesses (0,35mm) become huge. I don't know how others think of this, but I don't need different line thicknesses in the drawing window at all but only for print preview/printing. For all I care the lines in the drawing window could always be 1 displayed pixel wide. This could simply be made a preferences option.
2. Rotating stuff
It is very clumsy to make items line up with lines that are not vertical or horizontal. To place, say, a piece of furniture against a wall with some odd angle I first have to measure that angle and then rotate the block by the same angle. Why can't I just select the reference point and then snap another point to a line?
3. Stretch tool
I find the "rectangular-only" selection mode very limiting. It would be nice if the tool permitted all the standard selection modes. In addition I would somethimes find a "four point" approach helpful: two reference and two target points, which would enable a host of possibilities like rotating, scaling, and skewing the selected nodes.