I don't particularly like the font, although I only really object to the theta.

There are other nitpicks: The pi looks too italic to me, though I can't really say its wrong (whatever "wrong" means). The spacing between the integral sign and the integrand is too big -- but this is a common problem even in real LaTex.

Overall, it looks decent but just not as nice as the maths that TeX has been pumping out for decades now.

As long as we're nitpicking, the d in front of the theta shouldn't really be italicizes, anyway. I'd class that more as an input error than an output error, though.

Actually, many mathematics authors use an italic d while the upright d convention is standard in physics and engineering.

Is that to disambiguate it from the upright d in exterior calculus?

That would be funny, as that symbol was chosen specifically to overload with the traditional little-d notation from Leibniz.

Don't tell them that Microsoft developed the OpenType Math specification that LuaTeX uses.

The square root denominator looks too low to me. It makes the whole thing look lopsided. The TeX version looks better to me: http://latex2png.com/output//latex_9c2d6d68604c4a04a90acc777...