We are looking forward to seeing the mainnet release of Semux Smart Contracts.. Also very curious is you will be able to achieve anywhere near 5,000 txs per block!
I don't think they will be able to get 5000 per block, as they only have 1MB blocks. For simple contracts without a lot of data, they should fit. they hit 15,000 transactions per block in testnet with 3-5MB blocks for transfers.
I think dev team will release new perf for VM calls, but now I think it will be a matter of size of data that slows them down, not speed of transaction?
I think you can make expensive contract call that use a lot of gas, so will be interesting to see how much gas they can get in a block.