^^My stereo's just about useless to me because I like listening to the car much more.
I've got a base, so my redline comes in somewhere around 65-6700rpms, but getting up there is still fund and sounds amazing, even with the car as restricted and muffled as it is from the factory. I'm sure the larger engine sounds even better as it runs even higher.
Redline driving is not harmful to the car if you've been taking care of it and you're not pushing the car to that point before it warms up. I tend to give the car a lot of time to get up to temperature before I go past 4k. My normal driving and warm-up time driving tends to stay below 4k, but unless it's a really short drive I take it past 5k in some of the early gears to let the car make some noise. You can also feel the slightest nudge forward as the VarioCam adjusts for 4k+ operation.
If it were unsafe for the car, the redline would be down around 4k and make for a very frustrating car, lol. They limit it where they do because anything below that is safe operation. Like I said, as long as you're taking care of the car like you're supposed to, it'll do what it's supposed to.
And like someone else mentioned above, when you're on the track or autocrossing, you need every bit above 4k that the car has to offer if you're going to make those guys in the 911s start checking their mirrors and the time cards more often.
