This thread is not about which is better but why they are sooooo helpful.
I find I can pump my gain to read throught the ice not to find fish ,but to read depth without cutting holes.
Dumping a little water aides in the ice ducer's ability to read through the ice.
Cut a hole and grab some water in a pop can or whatever then you can keep moving until you find the structure your looking for.

Setting the gain as low as possible is important.you always want your bait to show up green or yellow.
Then as it turns red you'll know a fish is on your bait.
Setting your gain low will also cut out inteference although there are several interference rejection modes in most flashers.

Make sure you ice ducer is directly in the center of your hole.If you do this you can keep your ice ducer higher eliminating the chance of your line wrapping around the ducer cord.
More times than not you'll need to wet a hand to wipe off the bottom of the ducer puck which will help reading smaller baits.
Never use anything that would scratch it.This is a sensitive part of your flasher unit.
Ice can sometimes create unwated signals so you may need to get the ducer deeper in the water ,especially when the ice gets thicker.
Drilling your hole straight down will also aide in reading the water column better.

Once I get to the general area I'm popping holes,zig zagging up and down the breaks or just making swiss cheese if I'm over a hole that the fish hold too.
I most often then come back to read the holes.Reading the hole just after you buzz the hole may show nothing as the auger spooked those fish away ,but they can move back if you give those fish a few minutes to recover.
I'll keep cutting holes until I mark fish.No sense in setting up & hunkering down over a dead hole.

Then after locating the pods of fish I'll set up.I'll fish that hole as long as I'm marking fish.
If too much time goes by without marking fish after I've been catching I'll go reread those other holes.
The fish can move and to have those other holes already to fish come in handy.
I can just pull my porty over and I'm back in business.

I use a flasher to see under water.True you do not see the actual fish ,but the sonar signals tell me what they are doing.
It shows me where in the water column they are at.
I can also tell their feeding mood by how fast or slow they move to my baits.
I can also tell by how high they seperate from the bottom.
If you fish the same area you'll notice that some days those fish will rise pretty high to hit your bait and on other days they will not move much.
That allows me to upsize or downsize to match their mood .
I can see if there is interest or no interest in how I'm approaching them.

It allows me to work those fish higher in the pack as they are the more aggresive feeders.
Then when they clear out I'll move again....finding new pods of fish to work.
There should be no reason not to be on fish unless you just can not find them.