Is it wiser to own the best of the circulated grades or the worst of the uncirculated? Coin buyers seem to place high value on newness. If your primary reason for acquiring coins is to profit from the experience then it is probably best to stick with tradition and go along with the notion that any new example of a particular coin is always better than all the used ones. This may not be the best policy to follow if your goal is to assemble an attractive and satisfying collection.
By definition and based on current grading standards, a coin is uncirculated if it shows no signs of wear. Having no wear the coin properly deserves a MS-60 or higher grade. Uncirculated does not necessarily mean unblemished. A coin can be correctly graded as MS-60 or better and have a multitude of detracting features including a weak strike. One need only look at selected newly minted coins obtained from banks or the Royal Canadian Mint to confirm there can be some unattractive coins that must technically deserve the Uncirculated grade.
I consistently suggest to serious collectors that they investigate and consider collecting coins in the About Uncirculated grades. I recommend any review of the possibilities begin with a hands on inspection and comparison of AU and Unc coins while asking the question, “What am I really gaining by moving up to the Unc grade and does the gain justify the cost?”
I further qualify my encouragement to investigate the AU grade by mentioning that what we are looking for are “MS-63 with rub” coins. If an otherwise exceptionally nice coin acquires even the slightest wear it becomes an AU coin. To grade it otherwise would be wrong. Slight friction on the high points of the design is all it takes. This happens to be one of the few real rules that apply when grading coins. No matter how nice it might look, a coin that shows even the slightest wear is no longer Uncirculated-period. This circumstance creates an interesting if not exciting opportunity for those interested in building nice collections.
Like many dealers, I've encountered numerous coins that were probably Uncirculated when first acquired but have become slightly worn while in the hands of collectors. You don't hear it used much these days but we previously referred to such coins as having acquired “cabinet friction”. Mishandling of coins by collectors and others is a common occurrence. To me, mishandling is very different from intentional alteration as when coins are cleaned.
In closing, I will again remind that if your primary reason for purchasing coins is financial gain then sticking with Uncirculated coins verified as such by a reputable grading service is usually the best choice.