the start-up time as i said is the micro in the meter going through a self test, and a sanity check of the measurement circuits. the more features the meter has, the longer this takes. this also is true for meters with more decimal places. you said 28x series? seems to be that these have data logging functions, and that would definitely explain a long start-up time, because theres more than just measurement circuits that need to be initialized. if you need a meter which "boots" faster, try one with fewer special functions.