To put it bluntly, I don't like your way of speaking.
直截了当地说我不喜欢你的说话方式。
To put it bluntly, your temper is really very bad.
直截了当地说你的脾气真是糟透了。
To put it bluntly, your idea is na.ve.
直截了当地说你的想法很天真。