Large (blue-ish) cooler..... batch sparge. Two short pieces of hose, on from the HLT to the MLT, one from the MLT to the BK. No whirlies, no pumps, no issues. Beer tastes good.
Large (actually blue!) cooler..... fly sparge. Two short pieces of hose, one from the HLT to the MLT, one from the MLT to the BK. No whirlies, no issues. Beer tastes good. And it doesn't take any longer than batch sparging. And once the input/output flow to the MLT is balanced (takes about 30 seconds of messing with two ball valves), I sit and drink a beer until everything has drained. No reheating sparge water, no stirring, no re-vorlaufing.
Don't worry, I've batch sparged, too. I prefer fly sparging, but only slightly and probably only because I started out that way. Do what works best for you, obviously.