The 1854-O Half Dollar had the largest mintage of any of the With Arrows type. In fact, the mintage of the 1854-O Half Dollar was the largest the series had seen since 1836. Thus, in terms of value, this date is very affordable in most grades and it offers a lot of "coin" for the money. Mint State examples are fairly plentiful and can be obtained in MS62 to MS64 with ease. Even MS65 and MS66 examples are available in sufficient quantities to meet most collector demand. Above MS66, all bets are off -- this is a very tough date in Superb grades and it is a true condition-rarity in MS67.
Occasionally, 1854-O Half Dollars suffer from an insufficent strike, but strongly-struck examples also exist.