id avoid the capsule. as mentioned, it is likely containing filters, as few users/vendors have 0.0001g (0.1mg) accuracy scales and even with one weighing 600u would be quite difficult and timeconsuming.
the only benefit of the capsule would be that it is sniffable, whereas a blotter is difficult (not impossible) for nasal use.
blotter is easy to transport, cant be crushed/snapped accidentally, looks cool, and apparently has a higher dosing. that said, lower dose blotters might be easier to adjust your dose with, you just need a few more. (ie: with 1mg tabs, trying to get a dose between 1mg and 1.5mg (1.5tabs) would be very tough to split the tab. whereas 2*600ug would be easier to work with for that dose range