The amendment process is very onerous. 7/10 provinces haven't ever really agreed on the colour of the sky, let alone something as important as new constitutional rules. It took some very special backroom wrangling to pass it in the first place and I don't see a path to amending it during my lifetime. Meech Lake came close and very nearly broke the country.

The notwithstanding clause was necessary to get it passed at all, but really takes some of the teeth out of the charter of rights and freedoms. When parties hold majority control of the House of Commons or a provincial legislature a lot of what keeps their power in check is mostly norms it turns out. One of the few actual laws that would really impede them is the charter, but portions of it can be ignored.

Overall I'm very happy we have the 1982 Constitution Act, but I certainly wouldn't offer it up as a blueprint if someone came asking for assistance in drafting a constitution. The Charter itself as a portion of the larger constitution (minus the notwithstanding clause) is a very special piece of law that deserves some recognition internationally, but as a whole it wasn't even 10 years before the real issues were exposed with the whole document.