POSW (Poswallet) seems to have bottomed, I doubt it will get any lower. Masternodes are coming in july and some other updates. The service may become more attractive after they add ETH support as ETH will go PoS eventually. I think it's a good hold to see what happens, considering it just can't get any lower, and you are supposed to buy the bottom.
i dont think you can trust Poswallet to start start staking your coins , there are users reporting that the wallet tries to scam them making their balance disappear , if you would use it i suggest to not put huge amount of coins in there