Purchased my Z there back in 05 when it was Power Nissan... did my 'first free service' done there. They had some of the worst service e.g. 20 mins to bring my car out from when I requested and grease marks on the interior ceiling fabric.
I am not sure if the change in management also changed their service dept but beware and pay careful attn to your car.
I did have good service at Tustin Nissan but that's if I have to go to a dealership.
All my business goes to Corner3 Garage in Lake Forest. Steve is a Nissan master tech, and Nima is excellent in communication and taking care of you. They are well known in the SoCal Z and Maxima forum community.
Check them out: