I too find the speed tapes to be much more difficult to read quickly than a standard ASI. I have a feeling it's because in my brain on the old style I'm not actually reading 100kts per se, I am reading the hand at the 3 o'clock position and knowing what that means in terms of my energy state and any limitations. In addition I can quickly see how far that is from the stall (end of the white arc) or whatever it is I'm trying to get my speed to or keep it away from.