As of now, there is no multi-cam editing in Resolve, this might be an issue for some. Also, not sure if there is a way to export audio tracks into another program. This is something to consider.
I will say that trimming and keyframing looks very nice. One of the biggest drawbacks in Final Cut Pro (any version) has been the lack of good keyframing capabilities. Motion and After Effects are far superior in this regard. Resolve will have great keyframing as well.
The trim tools, while sufficient, in FCP are really all that great. A four up display would be nice for sliding and slipping. Really would like to see what is going on either side of the edit.
I would probably use FCP X, at least for now, to add transitions and for some other finishing tasks. Once there is more support in Resolve, it will become the primary editing tool. For quick motion graphics, going to stay with Motion as it can get the job done.
I do think Resolve will be great at editing but is it ready to be considered a replacement? My two cents, whatever it is worth.