The Zoop is a good entry-level divecomputer but it has limitations. AFAIK it cannot be used in gauge mode and it has no backlight (which some see as an advantage and others as a drawback) The Subgear XP 10 has abacklit display but no gauge-mode, the Oceanic Veo 2.0 cost about the same and offers backlight, free-dive mode and gauge mode, you will not outgrow it, it can serve as a backup for your Petel once you get one 
Look at a number of dive computers at dive sites and let the users explain the functions they use, then make a list what options you want the computer to offer.
Look at a number of dive computers at dive sites and let the users explain the functions they use, then make a list what options you want the computer to offer.