For my money, I think it comes down to how strong you are and how strong you plan to become. If you're a big strong sprinter type, then they would be a good buy. But if you're much less than that, then I think the difference between these and your Teschner or perhaps the current Dolan DF3 is minimal, and then there's money left over to sink into some other go fast bits.
I would love one of these and would buy one, but they're a little small for me. It would be fairly unique as there wouldn't be too many around.