I've had Delta, Charnwood, Axminster, NuTool and Record morticers, all do the job fine if you accept the limitations of smaller motors, chatty hold down clamps etc. (Maybe not the NuTool one so much, it was pretty dire). The Axminster one you provided the link to is by no means the least capable of these, similar to the Charnwood and Record with x y table and a decent bit of weight to it.
As long as you're making stuff of an appropriate size and take your time then it's all good, one of my favourite power tools as I don't have the time or patience to hand cut mortices but it is a satisfying way to join bits of wood together.