I haven't fully wrung mine out yet (too many projects and too little funds) but it is good for any .454 loads. Bowen will make a 5-shot conversion for you with a custom cylinder, but he'll also fit a .454 SRH cylinder to a Redhawk as well. Remember, these cylinders are made of special carpenter steel that will take the extra punishment and allow 6 holes and still maintain adequate strength, while Bowen's and others are made out of 17-4 stainless. Incredibly strong in it's own right, but not quite carpenter's levels.
I'm sure Instigator will chime in. His 7.5" conversion was my inspiration. I believe he has fired full-house loads, but not positive. Personally for me, I like the Redhawk frame better than the SRH and the unfluted look as well.
I do have a .480 Ruger cylinder waiting for this same type of conversion.