You must find a balance though. I would prefer a canned comment solution with good discussion over a unique and hand coded comment system, with flame wars and t

You must find a balance though. I would prefer a canned comment solution with good discussion over a unique and hand coded comment system, with flame wars and trolling any day. As for using a cms, it really depends on what cms you use I suppose. Coming from a wordpress background, I can say I am often surprised as to what sites are using wordpress in what ways. While some CMS's restrain you to certain looks etc, (if only due to difficulty of customization) others allow you almost infinite customization. As for Tumblr, the rigid theme guideline and review process, the small (when compared to competing products) selection of themes, and the resulting quality of the themes are part of their unique and yet similar ecosystem and it is part of their image, whether its for the best or not, it seems to be working for them.