You need to say the wattage you want. If you want any one receptacle to handle all the rated wattage or if having one that shares the wattage among the receptacles--which is no good for whole house, eg.
A typical 3000w with three receptacles will do about two on any one of two 15s and the third 15 can pick up the other 1000w, eg. Some 1000w are actually two 500s so can't run anything over 500, but can do two of those.
You have to phone their tech supports to find out the truth about all that. The store salesmen won't know and the users' manuals are vague.
On quality, I would look at the store's return policy. Some stores say you can only deal with the product maker for any complaints.
