I’ve owned a couple pairs of wading pants at various times. They’re ok. Though they’re not really any cooler than chest waders, and from that perspective I find them disappointing. Here’s why I think:
Chest waders go up higher and have more material above your waist clearly, but they also have an opening at the top to allow for some air flow and ventilate heat. Waist highs cinch around your waist by design, to hold them up, allowing no ventilation out the top. Yeah, my lower chest area may be cooler in waist highs, but my legs get significantly hotter in warm weather in them. Overall, the net experience is about a wash for me.
If I find a pair on a good deal, I’ve bought them before for a small stream brush busting pair to save mileage and wear off a good pair of chest waders. And I would buy them again for that purpose, but all in all there’s not much of a difference than chest waders in terms of comfort. If you’re going with one pair for all around use, get chest waders IMO.