Limited in supply is always good but for ETH I'm not sure as the smart contract use might grow very demanding in future even over billion pieces of ETH, I think its better if ETH has no limit
I dont think unlimited supply is good for ethereum. If ethereum have unlimited supply, i am believe the price will not reach this far. Its better if ethereum supply limited on 200 million and i am believe the price will rising
Since most if these coins value are really being affected by the demand and supply of it, I think it is better to have limited supply for now that the adoption rate is still very low, if the supply is limited, as demand closes the gap, the price will continue to rise, because as supply of ethereum starts becoming very low, it will continue to make ethereum scarce to get and as it become scarce, value will surely increase.
This is one of the tactics that Binance has been using in appreciating their coins, that is why most times, they also buy token from clients and when they do, they burn the token to limit the supply.