I would go with the 44 unless you already own a 10mm Glock and like the idea of sharing ammo.

I bought a 610 in the early 90s after the 10mm auto I had broke. A few years ago I bought a S&W 69 in 44 magnum and sold the 610. The 610 was great gun but I found the 44 did everything I want a revolver to do better. More power than a 10mm when you want it and factory ammo ranging from weak cowboy loads to full power magnums loads that pack a bigger punch than any 10mm load. Of course reloaders can pick any power level they want with a 10mm revolver but factory ammo is 40 or 10mm with not much in between. I also like not needing a moon clip or having to pluck the empties out individually.

Just because your friend prefers the big N frames like the 610 and 629 doesn't mean you will. At least look and the smaller L frame revolvers like the 686 (357 magnum) and 69 (44 magnum). I find they handle and balance better but that is subjective. Lighter than the N frames so there will be more recoil but that was a tradeoff I was willing to make. I do not shoot many full power magnums through mine though.