Interpolation based osx transfer function

I was testing `osx:?` echomouse-based transfer function with default parameters and noticed that when I use my Logitech M557 or my embedded touchpad the transfer function is really close to the system one (used glutExample).

However, if use Logitech G502 or Logitech M100 the libpointing transfer function is much slower than the system one.

At first, I thought that might be due to the resolution or update frequency of the input, but when I changed them (for G502), I have got the same behavior even for 400 CPI and 125 hz, whereas M557 uses 89 hz and 1000 cpi (logitech web-site info).

Any ideas?