I prefer bitcoin faucets, because it gives bigger rewards. Altcoin faucets is less popular and it means that owners of these faucets earn less income from ad services and they can't give high rewards. Also, there are much more paying bitcoin faucets than altcoins.
If you earning altcoins from faucets, you can hold and wait for price increase, which are not guaranteed. But same thing with btc - look in the charts, how much btc price increased in last months and years. And long term hodlers, who where earning from faucets 2-3 years ago, now have few, or even 10 times more expensive coins.
Which faucet do you think is more considerably pay high? Those premium faucets on faucethub?