perhaps the biggest disadvantages to the current bitcoin is, the amount that has limits. Well, if bitcoin always have the amount increased, perhaps it would be very nice to be distributed throughout the world. maybe so, bitcoin will be well received around the world.
first of all having a fixed maximum amount for bitcoin is a big advantage it has. because having unlimited amount or even a very big amount of coin available is actually a bad thing and can kill the price, it is simple supply and demand.
and also bitcoin has more than enough "amount" to be able to support a very large number of users such as in mass adoption. there are 2,100,000,000,000,000 units available for bitcoin which is called satoshi 21 mil+8decimal places. and that is more than enough.