Is it upgrade-able later if we don't purchase it with the measurement and color cloud firmware?
Yes. It's a firmware update you can do at any time.
With the upgrades is there any advantage to the iStar over iris360?
Yes. iSTAR is IP64 rated and is very rugged. It also has a longer exposure range of 120 sec - 1/8000 sec. iris360 pro will have an exposure range of 1 sec - 1/8000 sec.