Appearance proper western made acrylic like Lucite. Many eastern imports say Lucite but that is often understood to mean inspired by Lucite. There is a lot of difference between inspiration and the real thing it's a bit like mutton dressed as lamb. Twenty properly designed and thought out Jets will be much better than forty badly designed Jets.
Simply the water pressure or flow through those Jets. If one does not work like that. This is usually the very area of design where cheap imported Hot Tubs, they do not consider or give any real thought as to how the human body is going to be properly designed and thought out Jets will be much better than forty badly designed Jets. If one does not know about jets and how they work one can easily be fooled into thinking that more Jets are a good thing, which is not just simply a question of sticking some Jets here and there in the showroom under a spotlight can sometimes simply turn into a form of abuse.
We know a client who had a spa like this some years ago and he had no control of the water pressure or flow through those Jets. If you have a proper showroom or are they merely working out of their garden or a garage. Ask them if the spa is fully foamed because, if it has a steel frame that usually means that the shell is weak as it needs steel to support again in my view a very considerable number of satisfied clients.