I was going to do a long winded review/response to this question but instead I have three words...Fox Triple Crown.
The Milton bows are shooters for sure, otherwise they wouldn't be so popular in tournaments. They do shoot sweetly. But like Scott said, the fit/finish is utilitarian IMHO and more like what you'd find on a Samick etc. Customer service is a "?". Some people say great things. Others not so great. With as many bowyers that are out there its my opinion why bother with a less than 100% reputation?
Fox Triple Crown baby! A Ron King built bow will be heirloom quality and shoot with the best. I can send you some pics of a flat out breathtaking one if you PM me your email address.
A Fox will run a good several hundred more in base price than a 21st, with a longer wait time but it is well worth it IMHO.
The 21st bows are a great shooting 'tool' and are a decent value if you weigh performance vs cost, but again, IMHO...Fox Triple Crown