Is it the same motor plug that fits them all. Apart from jet/soldier... So all you need to but is one machine with plug then just buy the body's of the other machines? Looks alot of machines. Plus 4 different motor plugs I'm confused already. But I like the idea of the carts they look nice. But what makes them different to say t-tech carts. Well apart from the seals/spring i believe which you have mentioned. The needles the thing that does the job. Have they have been shaped any different? I've been mircoscoping needles lately and to be honest there isn't much difference between them not to pay £8 box to £30 box.