The comparison between Fongo and TextNow has been discussed in the Fido 3GB/$15 threads, including [WIP] Fido LTE Data Plan (Tech Discussion), however you've provided a nice summary. Re Fongo's number porting, it typically takes less than 3 weeks. IIRC mine happened in about a week.
"Better" is subjective. But if you can snag a Google Voice number, that offers unlimited free calls and texts in North America from a single interface. It also integrates with the Google web app suite like Gvoice and Gmail. And unlike Fongo/TextNow the number doesn't expire after 30 to 90 days of inactivity.
The main downside with GV is that the free number is in the US. That's not a major issue for most people who want to call you because long distance charges are so cheap nowadays.
veni, vidi, Visa