Always had mud flaps but thinking the fender flares might be better. Flaps tend to collect snow and ice that turns to rock and can get caught on things. Not sure if the flares make much difference for keeping some mud/dirt off or if they're just for looks. Anybody like on or the other better?

Mud flaps are required in some places, and popular in others where not required. In GA they are not required nor common. My 07 Tacoma is the only vehicle I've ever owned that had them and they broke off after 3 years. I pulled what was left off, trashed then and haven't missed them. None of my other trucks or SUV's have ever had them nor do 90+% of the other trucks on the road have them. I average about 1000 miles per year since the 1970's on dirt or gravel roads and have never had any body damage from rocks/mud coming from either my truck or other traffic on the road. In my experience as long as your tire/wheel combo keeps the tires inside the fenders mud flaps aren't necessary. If the tires extend outside the fenders then fender extensions or flares are the only thing that will help.

You get arrested here if your oversize tires stick out farther than the vehicle body, so the flares are pretty necessary. I'm going flaps this fall because I have powered running boards and the front standard size tires fill the hinges full of road crap and they don't work. New trucks are coming standard with flaps now.

Flares won't be any different. They'll still collect mud/water/salt/dirt and rust your truck

Where is "here".

I've seen as tires sticking out of fenders in WI or FL as I have any where else.

WI. has a rule like that and true I've seen some tires wider than the body too. It probably isn't a flagrant violation and the police likely don't enforce it much.

I have running boards that incorporate a front flap of sorts. I added rear mud flaps, not so much for the mud, but for the gravel. Without the rear flaps it "sandblasts" the paint pretty badly on each rear rocker panel. The first ones I put on were a bit too short and the rockers got hit pretty hard.

Fender flares were on a Jeep I had a few years ago. They were the black synthetic kind that added about three inches of width to the fender width. This kept some of the mud from flinging up on the Jepp when driving in muddy roads. I would rather have running boards for where I live and what I do with my truck.

I don't have flaps on my SUV and, so far, have no issues with the rear rockers.

I'm not aware of any such laws here, if there are they're not enforced from some of the vehicles I see. Just wondering if the flares protect the rocker panels as well as the flaps. Dirt roads, snow/ice, give them a beating.

I would think the mud flaps of today wouldn't do much different than the flares would. The ones in the 80's and early 90's, I think those would work better.