Tweet served its purpose :) . I am here saying we heavily use ropsten for testing our contracts atm. We are rather close to mainnet release and really don't want to add the task of finding another testnet on top of my team right now.
How bad would it be for you if there was a chain split?
Would effectively make testing almost impossible. Say a chainsplit between parity/geth. Half of us use parity, other half geth to test both clients.
How long would you manage without a non-broken ropsten?
I don't understand the question. You mean for how much longer do we need a testnet?
I mean if we had a split for four days, how bad would that be?
Pretty bad. At such point I would prefer a new PoW testnet.
A testnet is supposed to be light and easy to use, but Ropsten became way too heavy already. I don't mind if it breaks up and joins Morden in history.
For us and our testing consistency with older data is not required. We can easily afford to re-deploy to a new PoW testnet (that's lighter than Ropsten) that can be used by both clients. As long as such a testnet exists and we don't have to do that often.
or perhaps run your own private testnet for heavy testing?
What @veox said. It's not just us testing.
Well, you could gasp wait 4 days with resuming testing on the public testnet ;P
We are on a feature freeze so testing is our main focus right now. 4 days of development is a lot