Distortion is difficult to judge in this case because the camera was tilted slightly backwards and also swung a tiny bit to one side. After correcting this with an image editor, a bit of barrel distortion (maybe 1%) remains, but I don't find it objectionable in this shot (the picture attached is roughly corrected for tilt, swing and distortion). You can easily judge the distortion by looking at the red vertical line that used to be straight and is now a bit distorted by the correction process.
Sorry for messing around with your picture, Erik, I didn't want to "improve" your picture or anything (I think it is very nice and beautiful as it is), I just did this to make it easier to judge the distortion question.
Personally, I find that I don't like lenses that distort noticeably, but we have to remember that amount of distortion is always dependent on the object distance. A lens may distort noticeably at short distance but more mildly or not all at larger distance or infinity.