With Gentoo, I always sort of felt like I was more involved in my how my system worked (or didn't work). I had a better idea of what was going on in the system, sure, mostly because I had to edit config files by hand all the time. We have USE flags, sure, but setting a compiler option doesn't take that much effort or knowledge. We have CFLAGS, but most sane Gentooers probably don't do crazy things with those, and most people who do probably just Google and see what flags give the best results; it's hardly even necessary to know what you're doing, Portage makes it really easy to do anyways.. In reality though, beyond those things, how much was I really involved in how Portage worked? I typed
emerge something and then watched the screens of compiler text fly by for an hour. There were not many times when I went beyond that. I would guess that for the majority of people, that's about where it ends too.
If that's as far as you're going to go, then there's no point using Gentoo. As a means to download and install programs, Portage is not the best thing out there. In fact it's extremely slow and sometimes prone to breakage. Where Portage is good is going BEYOND that. Writing your own ebuilds. Configuring things on a very specific level before/while compiling them. Picking and choosing your dependencies. That kind of thing.
There were some times when I delved down to that level. If a gaim beta was released, I could modify an existing ebuild and then voila, I can install the newest version. Sometimes I wrote my own patches for some programs (openbox or FVWM) and I could easily get Portage to deal with those. Sometimes I would catch a program trying to install gstreamer-0.8 and stop it and make sure I got gstreamer-0.10 instead. That's where Gentoo shines. But I find that I don't really need that level of granularity nowadays, I guess.
People call Gentoo a hobbyist distro and I see nothing wrong with that. I don't think being a hobbyist distro is an insult; I see it as a strength. It's like a clock with the back removed so you can see all the gears turning. If your goal is to learn about clocks and mess around with them for your own enjoyment, that's what you need. But if your goal is to tell time accurately, it would be rather silly in a sense to use such a clock (unless you're such an expert that you can reliably make it work better than it normally would). I never ran all stable packages in Gentoo, and I think if stable is what you want, then Gentoo is overkill. Unstable is where Gentoo shines.