FWIW, few people I know who have purchased Vizios have been happy once the difference in PQ and the post-sales service hiccups that may ocurr were discovered. YMMV. Samsung might be a better choice IME if your budget really is $3K and could forgo the latest 4K HDTVs and go with a 2014 65" 1080p model. Unless the viewing distance was extremely far away in your media room, the 65 vs 70" won't matter at all. Study the Carelton Bale chart for more info regarding the realities of resolution/screen size/viewing distances.
*most important part of article is 'In conclusion' section
You really need to visit mom-n-pop HT shops in Canada that are not big box stores. See the difference in person between several HDTV makes/models, utilizing the same content on each one. IOW, bring in the same Blu Ray title, or ask that the same satellite or cable channel be used when doing any comparison. I've gone as far as ordering two (sometimes three!) different HDTVs, then doing a side by side comparison in my own home (and client's).
Amazon reviews can be useful to the layman IME, as are the various comments in AVS forums. There are usually dedicated threads to both individual models & makes/series, sorted by sub-forum type (e.g. LCD/LED, plasma, etc. Start looking around here once you identifiy specific models you wish to research.
Let us know if you have more specific questions, especially once you nail down specific models.