I have seen so many screw-ups by homeowners that I can't, as a rule, recommend it. Just because it works, doesn't mean it's a safe (or proper) installation. The 3-way & 4-way lighting systems are always suspect when I enter a home. I have, literally, never seen one wired correctly by a non-professional; and have seen them wired incorrectly even by professionals.
Can you explain in more detail what are the most common mistakes you see in three-way switched lights? I installed a couple of these in my house and they function correctly, but I guess I'm kind of curious what a professional would flag as "wrong" about these.
The 3-way, and especially the 4-way, lighting system can be wired up so many ways that I'd be hard for me to identify a most common wrong way. However, IMHO, the most dangerous error I have seen is the addition of a (typically romex) cable that, in practice, carries an unbalanced current load. The danger is that an unbalanced current running through a plastic jacketed cable can create a moving magnetic field, and cause induction heating in ungrounded metal parts nearby to the cable, such as nails. Imagine a person who wanted to control an overhead light over a stairway, but found it easiest run the circuit feed into one 3-way switch, to the light, then to the other switch. This can be done correctly, but the installer must make certain that current travels to the second 3-way and then
only back to the light, and that there is no other possible path for current to flow. One error that I have seen is that someone decides to add another light (or something else) after the original installation has already been covered up by drywall. Instead of taking that new cable from the center light fixture, they take a new switch leg from the second 3-way switch box, run it to their new light/load, and when they realize they still need a neutral to make it work, they run another cable from the nearest outlet just to get a neutral. This creates an imbalanced current load on the cables from the original light, to the 2nd 3-way switch, to the new light, to the outlet; potentially heating nails, drywall screws or staples along the entire path. When this happens, the junction box on the new light fixture, if it's made of metal, will be warmer to the touch than it should be, even with all of the surface area of metal to heat sink away the effect. A touchless current 'ticker' will go nuts several feet away from an imbalanced current load as well.