Juniper firewalls - SSG or SRX

Has anyone on Nanog had any hands on experience with the lower end of the new SRX series Junipers? We're looking to purchase two new firewalls, and I'm debating going with SSG series or to make the jump to the SRX line. Any input, especially about the learning curve jumping from ScreenOS to JunOS would be greatly appreciated. Thank you in advance. Jeffrey