Depends what speed you are getting on ADSL.
I don't see much need for the average user to need more than 10Mbps D/load speed.
So, unless you have a crud ADSL (mine was only 1.5Mbps), don't change.
With FTTC my download now hovers around 15Mbps. Very happy.
Modem for FTTC needed to be changed after 1 week, but new one is ok a month later. Only one reboot so far.
Also, consider costs, Infinity is a bit expensive.
Allergy Advice: This post may contain traces of Meerkats.