I've used 296 / H110 in .357 Magnum and .44 Magnum loads, almost exclusively with cast bullets. Accuracy is virtually identical with #2400 powder, though you might give up a little velocity with the latter. There is considerably more leeway in varying the charge weight with #2400 and you can use a standard or magnum primer with #2400. I realize standard primers are usually recommended for #2400 loads and they generally work fine, but on occasion I've found magnum primers to provide slightly better accuracy.
With 296/ H110, I think magnum primers are always recommended. I've used standard primers and they work fine, but I'm not recommending that since the books (real paper kind, not YouTube or Internet) don't.
Also, with #2400, you don't have to deal with the horrendous blast and fireball produced by 296 / H110, unless you like that and some do.