Like big country said, I've had some good experiences, and some real nightmares. If you get a 'smith to do the whole thing, better get a real firm price first. Yhis stuff can get expensive quick. If you can do the stockwork yourself, you can save some money if you know what you are doing. Some manufacturers advertise drop-in stocks, but most take a bit of finishing.
It's nice to say it is your custom rifle built by/for just you, but you can get more money in it than a good factory gun costs.
Another point is resale. It is usually harder to sell or trade a custom gun than a factory one. JMO..............