It used to be a good source for easily generating IP upon reconnecting. Is this still the case? Any new services that accomplish the same task?
They are good, just that like all of those type of IPs they tend to recycle the IPs pretty often. So as long as you keep a log of which account has used which IP, you should be golden.
For just a couple of accounts this will be doable. But if you're using lots of accounts, I recommend just doing a dedicated VPN to make the work flow more efficient.
VZW (Cellco Partnership) IP pool is vast and seems to work well. They also don't geolocate to any particular point other than New Jersey, so can be used with most any accounts.
Is Verizon Mi-Fi still good for random IPs? 
