Eagle SIR6123CB rods Vs stock.

If the costs were similar, I'd buy the new rods...Scat I-beam instead of Eagle though.
Yeah, I've always used Scat at the lower end of the scale.
Obviously there is a time and a place to use an aftermarket rod, then you need to factor in who's rod you want to use.
What annoys me is this whole " by the time you do this, you may as well do that (which in the end costs more)" attitude. I've noticed it a lot more in recent years, and it usually ends up with a customer paying more than they needed to.
The last virtually stock BB I did, the owner was told that it wasn't worth overhauling the heads and he should get aftermarket ones. The funny thing was, that assumption was made without even inspecting the heads. Turns out that the heads were pretty good, they were serviced and used for a lot less $$ than new ones. He was very happy about that.
In a case like this, new rod bolts and resizing them would cost me $280, so you can see that's a significant saving over $600(from a place like Summit) for a customer.
And not every rod needs to get resized when replacing the bolts.