To be perfectly honest, I don't think so. The F5.com website above is about 40K alexa, high traffic depends on your definition but an alexa terms to me that means 5K or better and based on the traffic specs you gave you are more in line with me as there is no way F5.com gets close to 10K visitors daily. Both my DNN sites are 20-35K alexa but I would not say they are high traffic, and I asked the sales guy at DNN if he could name any high traffic DNN sites and he threw a bunch at me including some name brands and small government sites but on looking through them there was nothing that was high traffic / high functioning like I was looking for. This leads me to believe there are no major sites running DNN and that is obviously not a coincidence and 100% reflective of the offering. Of course it is possible to run a high traffic DNN site, but just realize it's going to a lot of work and modifications - I haven't inspected the latest offering in awhile but clearly just from accessing this forum and waiting over 60 sec. for the image manager to load (LOL) obviously there are still issues out there. Is it worth it? Well, you have to give more details about what you want to do to answer that, if in fact that is what you are trying to figure out. I would make the general statement if you are looking to build a high traffic, highly usable community based portal there are many issues worth considering, but really it all depends on what you want to do. Just because nobody has (apparently) done it yet, doesn't mean it cannot be done, but at the same time you cannot expect the core functionality or any of the available add-ons to carry you into website superstardom. For what it's worth, I got stuck, for better or worse, in DNN early on in our core community project and have stuck with it and at this point there is no turning back, and as it is already one of the higher traffic DNN sites and we are putting a lot more work into it I would be pretty shocked if one day hopefully not too far from now it didn't break that 5K alexa barrier, or get 10K visitors in a day - so it can be done and I do intend on doing it. Just make sure you calculate everything before making a move, if you want to ask anything I will try my best to help :)
And if someone DOES know of a high traffic website - based on the OP's definition or close - PLEASE post it as many of us I am sure would love to study it, I would even love to just see something highly usable with a lot of functionality even without the traffic.