DHC, Should I vote for the merger with OPI ?

I have some shares of DHC Diversified Healthcare Trust, I need help understanding how I should vote regarding the merger with OPI.

I've done some research but it seems these REITs have some shady people behind them, so not really sure what the end game is for them.

This is currently my best performing stock, so I'd like to figure out if I should sell it or hold.