I've just tested it on a breadboard this evening and it works quite well.
I used a 5V supply and the CD4011 instead of the 4069.
The hysteresis was around 0.5V which is to be expected given the resistor values used. I tried omitting R4 but as I predicted, will operate in the linear region when the input voltages are close to each other so you should always include a hysteresis resistor to prevent this.
I didn't test the common mode range but I suspect it won't work down to 0V or +V, depending on the device used, with the IC I used, the output voltage of a single gate with a feedback resistor was 2.66V which means the inverting buffer will saturate when the input voltage goes below 160mV. I suspect this will be different if a different IC were used so it's probably good practise to assume the common mode range will be a couple of hundred mV of either supply rail.
This is certainly a viable solution if all you need is a comparator, have a couple of logic gates to spare and don't want to use another comparator IC, for example, it could be used to monitor the supply voltage or part of an IR beem break detector.
This circuit could also be used as a an inverting or non-inverting Schmitt trigger with settable hysteresis, by replacing R2 or R, respectively, with a potential divider consistinge of two 2M resistors connected accross the power supply.