I didn't say anything against linear arms, or in preference of pivoted ones. If we're talking about the theoretical ideal for how a cartridge ought to traverse a record, of course the answer is linearly. I just don't feel that skating forces in particular are all that big a deal -- that they can be adequately compensated for, and don't affect the sound all that much. Your anecdote about tracking force seems intriguing, but I don't think it qualifies as definitive evidence on the effects of skating forces, or in choosing which type of arm to go with, due to uncontrolled variables. To me, the weakest points of any tonearm design are probably their resonances, followed by their bearings -- and then their geometry -- and as a breed, linear arms don't solve the first two problems any better than do pivoted ones, if even as well. I think there's always a trade-off involved either way you go, but that both approaches can be made to work acceptably well if not perfectly.