I'm definately not a teeny-bopper, but I wouldn't be interested in the RX 400 if it had a 4-cylinder with V6 perormance. We travel over the Sierras and up roads like the grapevine into LA. We need a car with the ability to put out sustained power to get up those. With a 4-cylinder on that large a car, I'd be concerned we would get to a point where the batteries ran out and we would be on gas engine alone for an extended climb.
Test driving the RX 330, it wasn't quite as responsive as I would like especially for rapid acceleration to get up to speed on on-ramps and such. I don't mean it was terrible but it was a bit under-powered at times. Also, its gas mileage was a little less than I would like. So an RX 400 that gets a bit better performance and a bit better mileage is just what I want.
We drove the Prius, but were concerned about its very low ground clearance. We sometimes go down imperfect dirt roads and I'd be afraid with the Prius that a rock would rip out something.
From what we've heard at this point, the trade-off of power, mileage, space and comfort in the RX 400 will be perfect for what we want.
By the way, I have heard from multiple dealers that the RX 400 will not have wood so they will be catering to that green desire. One dealer said that there will be less wood in all their 2005 models and that Lexus was looking for more renewable alternatives to old growth woods. I care about the environment, but I'm not a vegetarian and I have no problem with leather.