Hi Drew,
Of course it is a judgement call, but this is a lovely scene and I can't imagine it being improved by 'artistic tilting'. If you did tilt on purpose then I think you made a poor choice, but my guess is it was an accident. If that's right, then I just want to add that it is an accident we all make, so one of the first things to do with landscapes is check and correct the tilt.
Tom is right about the exposure. This looks like what I would expect a camera set on automatic to do with a scene that has as much range between dark and light as this one. Many cameras lock exposure when you partially press the shutter, so a quick and easy approach to getting clouds exposed better is to angle your camera up to include more sky and partially press the shutter, then recompose. This works even with cameras that don't have manual control over exposure. To get an idea about how much better the sky would look, check out the reflection.
Speaking of reflection, I like how you positioned your view so that the reflection of the mountains lands in the clear area of water above the patch of lilies.
Regards!
- KenF