"Between two foods, equally distant and attractive, a man free to choose would die of hunger before he brought one to his teeth." - Dante, The Divine Comedy
Generally speaking, I'd prefer the MS65. DMPLs are great, beautiful coins, however, the mirrored fields and frosted devices tend to amplify hits and marks. A lot of 64 and lower DMPLs tend to have a good amount of frost breaks, and noticeable chatter in the fields. Personally, I usually find those marks very distracting. Whereas a 65 is usually relatively clean, and with no frosted devices or mirrored fields, the hits are less noticeable. Of course it'll all depends on the coins in question. Once you get into 65, 65+ DMPLs, in my opinion they're some of the best looking coins out there.
If the DMPL was legit I would go with that. There are a lot of 65's out there and even 66's are available. I have not checked (I'm sure someone will correct me) but DMPL's are probably more rare.
Okay, make this interesting, as there is no coin under consideration in the question. Would you rather have an 1893s in MS 65, or an 1889CC DMPL? Now, that is the question. Assume both are beautiful coins.
89-CC is often found DMPL, but 93-S is not often found in 65. Might have to go with the 93-S. My initial answer holds, however, if we're considering a 64DMPL and 65 of the same date that are worth about the same. When this is the case, the 64DMPL is almost always far scarcer than the 65. PCGS population of 1904-S in 65 is 141, 64PL is 10, yet the price guides show them about the same.
Agreed. However price guide is not often auction reality in situations such as these. Supply and demand often dictate the market on specialized coins such as mentioned. DMPLs in higher grades that are not ugly with bag marks or battleship gray toning are scarce, as you pointed out. DMPLs are a rare occurrence comparatively with any coin, and fortunately they're still affordable in common date Morgans. However, in my above example, both would be very unaffordable: The 1893s in MS 65 is insanely expensive--auctions often go way over price guide for an ATTRACTIVE example of that date. The 1889cc DMPL is also not common enough for auctions to generate a lot of interest for an attractive example in MS 64 for that date. Which one would I rather have? I think the 93s, as a key coin like that (assuming that it was very attractive) has a degree of exclusivity.
Believe it or not, it's technically possible to acquire the four 1889-CC's in MS64DMPL it would take to even-trade for an 1893-S in MS65.
I have a definite opinion about which I would choose - but I know my collecting preferences. The decision would have to be up to you. Which coin do you like better? Which coin is more attractive? Which coin fits your collecting goals better? Which coin matches your set better? The decision is a very personal one - and one which gets at the heart of who you are as a collector.