So I continue to use the 640 LTE as my daily driver. I updated it to Windows 10 Mobile using unofficial methods which restored a significant amount of functionality to the browser and system in general. It cost me the Here Wego navigation app though.
The absence of WhatsApp and Signal are the two most noticeable missing links. But I d have telegram working.
I'm pretty satisfied with the situation at this point.
Wow I thought I was hard core! I have the 650 and I find it painfully slow now. On 950/950XL now.
But 'works'? Ermm...
I can check email, calendar, but have to use work-arounds for some accounts (e.g. iCloud). The browser is pretty good except when sites check specifically for Safari or Chrome.
Microsoft To-Do stopped syncing, have to use work-around.
The default weather app just broke (for some locations only)...
For the maps, I'm ok with the Microsoft version.
No issues with voice calling and SMS, but at this point, it's dipping close to feature phone level. Can't even get the emergency alerts. Things seem to be getting worse all the time. Even my older Blackberry 10 devices are generally able to maintain more functionality! At least they don't seem to lose functionality on the built in apps. I know with AT&T, at least a couple years ago, I still got the emergency warning on my Passport