As someone who has used Talkatone/Groove IP/Vonage and Hangouts, a lot has changed in the last year or so.
1.) RAM has improved. The first phone I tried VoIP calling on was a Samsung Galaxy Exhibit II. It had maybe 1GB of RAM. Issues like the phone not waking out of sleep quick enough for me to answer were major issues.
2) Integration is better: Things were hit and miss with other providers but with Voice and Hangouts in-house, the compatibility is a lot more evident.
3) LTE: My Nexus 4 experience was better than my Galaxy Exhibit II but my Alcatel Idol 3 w/ all T-Mobile bands is even better. I made an international VoIP call while walking around for 40 minutes and it was great. Before, I could make a decent call over HSPA if I stayed stationary, but LTE allows much more freedom.
I feel like I am becoming a cheerleader for Hangouts, but you really owe it to yourself to try it again imo. Especially since it is free. Project Fi uses Hangouts for all Wi-Fi calls so you can also check there to see if any complaints are being lodged by Nexus 6 users,
Thanks for all info. Vonage and hangouts works on wifi only or works on LTE too?
Do we get the initial 10gb data stash on this plan?
Ian B