For those that love big recoil, those calibres are probably a good bit of fun.
I'm just not one of those guys.
For me the 44 Magnum and 45 Colt are plenty enough for me. Don't really load big bad rip snortin loads in either caliber. I've been trying out Goex and Trail Boss in my 44 Maggie LOL. The Goex loads are a bunch of fun!! ... and the near max Trail Boss loads are real cream puffs for nice relaxed shooting.
Bob , you and I seem to have very similar tastes in sixguns.
I tend to like revovlers that are a packable size.
Got my eye on a 44 Mag 5 1/2" Redhawk. That is prob about the upper limits of "packable" for me. Can't quite seem to talk myself into it though. Diggin' the single actions more latley, but the RH is a bit of an eye catcher with it's factory wood stocks.
... plus for me, it's just very practical to load cartidges that have very available componants. I load mostly 38/357, 44 Mag, and 45 Colt. I don't ever see lead or brass for those big calibers around these parts.