It hasn't given me nearly as much trouble as RPM. Packages don't refuse to install over tiny incremental changes to libc, the installer won't cough up its own skull if you upgrade your kernel, and Gentoo's basic
package database is so extensive that I almost never need third-party overlays to find what I want. It's also far more easily browsable than the general anarchy involved in binary packages.
Besides, you asked what was best for
programming. Binary distros work so hard to separate the programming side from the binary side because it's a big, awkward thing no matter how you cut it, there's bound to be a tradeoff.