My experience with Varget was IDENTICAL to MarinePride's.
I've never used N133.
I use either RL-15 @ 27.5gr (near full case) for 3,250fps from 20"bbl or 26.9gr of BL-C2 for about 3,200fps w/55gr bullets. (24" bbl gets about 100fps more, my 18.5" bbl Rem M7 identical to maybe 50fps less). Either of these give top accuracy and near max velocity in all guns I've tried them in.
I've used H335, H4895, IMR3031, H322 and others in .223 but prefer the two mentioned above.
H and Imr4198 have given good performance is some guns, but is not as fast or consistent as the RL15 or BLC2.
If I were to load a high volumn of .223 I'd probably use some WC-846 surplus powder.