implements trencher and fail mower for mini excavator anyone have any experience?

I am interested in picking up a newer 8000lb ish excavator, and looking for input from anyone who has experience running a trencher or a flail mower on a machine of this size. Curious how they work out.

Ive never used either. Are the trenchers worth while or are I better off with a trenching bucket and just digging the old fashion way?

what about the flail mower, the videos online of them grinding trees up to 4+" diameter are very cool, will a 8000b machine give me decent results?

Are certain machines better then others for these attachments? higher flow I guess..

thanks