I know of at least one other person who has been using the castrol import and says they've had good results.
Also, I bought my car with about 62,000 miles on it, and the fluid needed to be changed. Place i bought it from changed it for me before I picked it up, fluid was nice and fresh. It had significantly darkened within 10,000 miles, so I started doing a drain and fill with a synthetic. These transmissions run really hot, and I'm hoping the synthetic holds up better. So far so good.
Also, there is a fill-port, but it's hidden beneath the airbox, and when I tried to loosen mine, it was jammed tight and I just ended up partially stripping the torx fitting. So I left it alone and just used the dipstick.