My issue with the unit has been resolved. After contacting Quick USA customer service and requesting a replacement hose, they offered to replace my unit with a 957DW instead (rationale is that they believe it would be difficult / annoying for me to attempt to replace the hose myself). I paid for shipping my 957 to them, they paid for shipping the 957DW to me.
The 957DW I received is basically identical to blueskull's. Although the hose on this one is also a little kinky, it's much less severe than the unit I returned and does not interfere with positioning the hand piece. To my ears, the brushless motor sounds slightly less noisy and noticeably less "buzzy" than the brushed one. Curiously, claimed power consumption for the 957 W models is 400W vs 580W for the 957 non-W models.
I highly recommend the 957DW, although it confuses me why there exists a W and non-W version in the first place. Quick USA customer service is also responsive and easy to deal with.