Hi,
i do not find that it is significantly more. i.e. spot +1.49 for Round vs +3.39 ASE (American Silver Eagle). (If you watch for sales you can get ASE's even cheaper). Whether silver is at $22 or $36, at minimum I have always seen the same spot plus+ pricing on average for each. So relatively, you would not lose, you just having to put out more per ounce. However, the upside is the ASE could make some additional gains numismatic-ally. Personally, I like having the coin over a round, and just to have some non-coin silver I get bars just to have my non-silver be different.
Have fun stacking, Mikey