Speed strips or Speedloaders? Hmm
Speed strips are good for the range, but they take quite a few very deliberate motions to complete. Eject shells from cylinder, whip out speedstrip, and while keeping your focus on the gun and removing your danger scanning abilities, line up cylinder, pluck in 2 rounds, rotate the cylinder by thumb a 1/3 turn, pluck in 2 more rounds, rotate the cylinder by thumb a 1/3 turn, pluck in 1 or 2 more rounds (if its a 5 shooter or 6 shooter), knock the strip away, close cylinder, and reassess the situation.
Gee, that's quite a bit of work. It works best when standing still because of the dexterity involved, but imagine trying to retreat and do all of the above steps.
Speedloader: bang bang bang bang bang, [empty], eject spent shells, whip out HKS or Safariland unit, take a second to line up the noses of the rounds into the chambers, twist or press the knob, knock the loader away, close cylinder, and reassess the situation.
A Speedloader means your eyes are focused on the reloading task for fewer seconds than with the speedstrip. Of course with either you can fumble a round or two, but in all honesty the speedloader is the better tactical option. Speedstrips: too many microsteps involving rotating the cylinder and thumbing and twisting rounds into the chambers, and more seconds will go by in which you are a non-combatant / target. But they do work great at the range in that they give your speedloaders a break from some wear and tear.