Here's my take, for what it's worth.
The American Silver Eagle is minted and guaranteed by the US government. For this reason alone,
ASE's will retain a small premium over all but the rarest private mint silver rounds.
The largest bullion dealers typically purchase their
ASE's from the US Mint in what are called "monster boxes." Each monster box contains 25 mint tubes. Each mint tube contains 20
ASE's. The coins are brand new and are commonly marketed with the designation "brilliant uncirculated." When you buy these coins, you're buying silver bullion, plain and simple.
The US Mint also sells proof and uncirculated versions of
ASE coins directly to both companies and individuals. These coins go through a unique minting process and arrive with a certificate of authenticity and in special US Mint packaging. This process creates a uniquely beautiful coin with a numismatic value above and beyond the simple intrinsic value of the silver it contains. If you chose to collect these coins, it is essential that the coin, all special packaging, and the COA be retained to preserve this additional numismatic value.
Depending on your buying objectives, both ordinary "brilliant uncirculated"
ASE's and US Mint "proof"
ASE's have their merits. Since one of
my silver stacking objectives is wealth preservation, I prefer to buy the bulk of my silver in the form of brilliant uncirculated
ASE's at the lowest possible cost. Now, since my other objective is coin collecting, I may also buy a proof
ASE or two for a given year. However, since the premium on proof coins is substantially higher, my proof purchases will never approach my bulk BU
ASE purchases.
But this is just how I choose to buy my ASE's. There are other collectors/investors out there who will only buy proof coins for their collections. There's no right or wrong. It's just whatever works for you.
Ultimately, it all comes down to discovering your own buying objective(s) and developing a purchasing plan to get you there.