My wife ha a WRX that is a 5-speed and I really dont wish that my Z was a manual. I have plenty of fun with my car. As far as repair or replacement as long as you dont have crazy HP you can find auto trannys all day long. Most of the clips that come over from Japan these days have an auto, seems like everyone is trying to sell them. If you do have crazy HP there are reputable builders to go with that supply trannys that will support just about anything you can throw at it. If you have grown to love autos then get one. I know that autos with low miles are a little easier to find than 5 speeds with low miles. If you drive an auto and it is everything you want out of Z then get it. If it is lacking in something and you think that a 5 speed would cure the lacking then get a stick.
I'M A HOOKER My other ride is a CH-47D "Chinook" helicopter