Basically, yes.
Because many Bobs used to think it’s all automatic and that the DEx can take 0.4 BTC from their address after they log out, matched orders used to expire because Bobs would end their Counterwallet session and forget. Then Bobs complained and developers removed anything involving BTC from Counterwallet.
You can still do this kind of trade on the Counterparty platform, but just not in Counterwallet (you’d have to use the API or CLI, both of which are bothersome). I think Indiesquare Wallet allows you to use the DEx and you can use the same pass phrase as for your Counterwallet (if you wish).
Poloniex has been problematic because of a suspect Counterparty bug as I mentioned in the other topic.
DEx is great if you need best reliability and can find someone interested to trade (because due to the lack of “BTC Sell” functionality in Counterwallet people can’t sell or buy BTC so BTC liquidity is very low to non-existent) and preferably Indiesquare or technical user who wants to buy or sell a non-trivial amount of XCP (say 100 or more).