Hi and welcome to the zone,
I have no personal experience of these machines but I do know they have been mentioned here a couple of times. If you do a search you should find something and you could post there asking for opinions.
I would question the seller and get his opinion about the kind of work (mainly the aluminium milling) you want to use it for; it may not be rigid enough. He’s a member here so he might jump in and provide some information about the capabilities of his machines.