http://digiphoto.techbang.com/posts/4630-pentax-mx-1-evaluation-renewal-of-classic-retro-wen-qing-is-worth-losing-it?page=2
(in Chinese, Google machine-translated page here.)
A full ISO comparison with full test samples are posted. The reviewer says that the IQ is not good enough starting from ISO800 with the significant loss of details and the appearance of more noise, which is considered not acceptable. It is further concluded that the usable ISO range is of ISO 400 and below. Judging from the samples, I am afraid that the Q actually performs better, frankly.
In fact, I think this review is quite fair and objective. The MX-1 is too large, thick and heavy to handle, especially for a P&S camera. So the user-friendliness of it is just so-so. But then the IQ of it is just average, also.
Last but not least, it is confirmed that full optical zooming is not supported during video recording of Full HD movies.