We know Ether as the second most capitalized cryptocurrency and all along it's transaction fee and confirmation time have been impressive, but presently as its demand and adoption have soured, we have started to see that high cost of transactions and delays isn't something unique to Bitcoin. It happened to become quite pronounced with Bitcoin only because it's the flagship cryptocurrency but apparently that's the lot that awaits all cryptocurrencies especially as they became more popular. At any rate, efforts are being channelled to arrest the ugly situation and it's hoped that Lightening Network would be able to do a good job at that.

For. now what I can say is the disadvantage of Bitcoin is that it takes an institution or having a deep pocket to be able to mine it  and  that could lead to centralization.