I don't own a steel framed 3rd gen, but have some time with a range rental 5906. If I were to go full sized 9mm, I'd find an '03, the above mentioned 915, or a 910. (The 910 is the Value Line version of the 915 and has some changes to make it less expensive, a la the 908 compared to the 3913.) The 5906 has a lot of weight to tote when shooting 9mm. If wearing a gun that heavy, I'll pack my Colt Combat Commander to kick @$$ and take names. And I haven't worn that pistol in years except for social occasions.
As far as wear goes on the aluminum framed guns, I don't worry. If I were going through thousands of rounds a month, yes, it would be a concern. However, I'm lucky to shoot a few hundred a month. In good times, maybe 500, in bad times just a couple. I discovered awhile back that as far as range practice goes, more isn't necessarily better for me. I usually shoot a max 200 rounds of 9mm and then clean the palate with about 100 or so .22s. More rounds than that, I start to lose focus and get sloppy. At this level of shooting, a well cared for alloy gun will lasted longer than I will.