I haven't tried Magpul AK mags. Their AR mags are supreme though.
I prefer the steel AK mags, that's all I've ever bought. I like those 1/4" thick feed lips - I don't think you could damage those with a sledgehammer.
I disassemble my AK mags and if there are any dents in them, I push them out from the inside with a kitchen utensil, or if the wife is around, I use a wooden dowel instead. Then I put them in a bucket of scalding hot water mixed with OxyClean (you'll probably find that with your wife in the laundry room). Agitate, let them sit, agitate, sit, repeat. That OxyClean tends to foam up a bit, so do it over the carpet only if your wife is out of the house. This gets them pretty clean. Next up, I run them through the dishwasher with powder detergent. Hint: This is NOT recommended if your wife is fussy about bits of grease and cosmoline left behind in the dishwasher. Women are strange like that. That comes off easily when you scrub it with steel wool, but if the dishwasher is still new, you might want to try a soft sponge instead. Dry them as best you can with paper towels, then throw them in the oven at low heat for half an hour or so to finish drying them (same caveat about fussy women - but you can spray lemon juice in the oven afterwards to help control the smell). Even after this, they will probably come out with a little surface rust on them, so sand them thoroughly inside and out to get rid of that. The kitchen table is good for this, if the wife is gone, otherwise do it outside. Then tie a string to them at some attachment point and hang them from a tree limb in the front yard for painting. Any old flat black spray paint will do. If there's any breeze, they sound like deep throated manly wind chimes as they're drying in the tree. And the neighbors will really like them too. If you want to lubricate them, don't use a wet lube (no oil, etc.) Use dry graphite spray. Use your leaf blower to get the graphite overspray off the couch cushions.