Since both are very reliable machines, I'd go for the company who will give me the best support. If you talk to Hirsch and feel comfortable dealing with them, then go for the Tajima. Another plus is that Hirsh is also a distributor now of Kornit (and maybe Mimaki)
DTG printers, and other equipments that you might decide to buy in the future. Maybe if you can establish a good relationship with them, you can get better terms in your future purchases. Good luck with your choice!