You can have a stiff back end. My FF29 is very stiff and when coming from my cro-mo Marin I noticed it immediately. It has advantages and disadvantages but can be mitigated by position on the bike, you soon adjust, tyre choice and pressure. The main thing I noticed was not my teeth rattling, after all, it's a hardtail but the back end skipping and chattering more. Changing to a grippier tyre, lower pressure and learning to keep my weight back compared to my Marin solved it. I wouldn't spend any time dwelling on that aspect of the review.