Buy a Custom Rod?
The short answer is that you can get exactly what you want. Factory built rods are uniformly good, and good values for what they cost, but what if you don't want a 9-foot, 4-piece fast action rod? Good luck trying to find anything else, except at premium prices. I recently built an 8'3" 6-weight, 3-piece glass rod for a classic caster who wanted a slow-action smallmouth rod for Missouri stream fishing. A few years back, I built a 10-foot 1-weight rod with a fighting butt for a customer who wanted a nymph rod for small trout on big rivers. If you want specific colors in guide wraps, or an exotic wood reel seat insert, or a grip that's not quite what factory rods come with, custom is the way to go.
When you buy a custom rod, you're buying craftsmanship. Factory rods are products of factories--mostly in third world countries where labor is cheap and the bottom line is the most important goal. Buy a custom rod, and you get something built by a real craftsman, who cares more about the quality of the product than the profit margin. Sure, most of the rod blanks come from Asian factories, but there are also some small-shop blanks made in the USA out there if that's important to you.
What you don't get with a custom rod is that no-fault, idiot-proof warranty that most factory rods have. If you break rods, then get a factory rod from TFO or Orvis and get it replaced for a nominal fee. But also know that you're paying for it up front in the initial cost of the rod. I'll stand behind my workmanship, but if you step on it and break it, it's on your head.