Hive Engine has been fairly reliable, but not without problems.
I am not a fan of the centralization of Hive Engine, especially in situations like LEO where there is $1.2M USD market cap but it only exists on aggroed's private server. SMTs can't come fast enough to allow token holders an decentralized secure option.
Situations like the one above is unacceptable, especially without any formal announcement or disclosure that I can see.
I think Hive Engine was a fantastic experiment to show what can be done with SMTs but we need a decentralized native blockchain solution that isn't dependent on one party.
wLEO for example has almost $400,000 USD of liquidity all resting on a Hive Engine token, that only exists in a centralized database running on a VPS. There is more than that that hasn't been moved over to a liquidity pool that has similar risks as well.
I have a STEM token for my STEMGeeks community that I am not entirely thrilled with the current situation, but the entire market share is less than $15,000 USD. I had more Steem stolen from Justin Sun and rogue witnesses than that.
Anyway, my opinion, it's probably fine but far from ideal. It's all we have right now though.
RE: What is going on with Hive Engine and Unstaking?