Bought one of these about 16 months ago and found the suction aspect of the device to be fairly good considering the size of mower in use. I rarely used the blowing function as I find it pointless chasing leaves etc. around the garden.
The bag on this device is connected to the main aparatus by means of a large, plastic, round bayonet fitting and this is the weakness that I have found.
Where the bag attaches to the said bayonet fitting the seam of the bag is uppermost when the device is in use, hence, as the bag fills all the weight of the bag in its expanded state hangs off the seam. Eventually, the seam gives way and a hole appears in the bag that is not possible to mend as it abutts to the plastic bayonet fitting.
I have checked around varioous places to purchase a new bag and nowhere seems to have such and item; I contacted Worx via their web page and filled in a request form and received no answer. I then called them and received very little assistance being passed around like the proverbial buck until, eventually, I was told "we don't make one, you'll have to buy another".
Not on your nelly mate! If I can add one useful tip to this it would be, before you buy any of these devices, check you can the spares.