listen on the QRP frequencies, and see what speeds you hear ! it won't always be straight key, but it's never be hugely fast, because the signals are just above the noise level, and if the sending is really fast, and there are fades, too much info gets lost.
More important for QRP, get the best antenna you can - if not a beam, a wire dipole, even if it's only 10 or so off the ground. Using a mobile antenna like a hamstick with QRP will get you no contacts - not efficient, so not much signal radiated, you won't be heard much beyond line of sight. also, with a horizontal antenna, you get a good bit of vertical radiation, so you get better local coverage out a few hundred miles through NVIS