with unlimited items? yeah a lot faster since it saves you around 3-4 seconds per item (3,5 average and 3 if you mash press). If EV training takes a minimum of 325 items (for 252/252 spreads which are the most common ones) per pokemon then you're saving around 18,95 minutes per monster. As for level up since most of the time I do breeds, that means another 99 items (rare candies) to use which add up to another 5,7 minutes average.
This is why I'm usually reluctant to do EV training and/or lvl up in 4th gen nowadays especially if it's a whole party -.-