The Poynting has more mounting options and is cheaper, the MobileMark is a bit smaller at around 6.5 inches round and lower profile.
Poynting has an integrated grounding plane for RV roof use and MobileMark requires an optional grounding plane available at checkout.
Both are great antennas but typically the Poynting is more popular because it is cheaper and has more mounting flexibility. They both clock about the same performance so you can't go wrong either way.
The MobileMark antenna in our bundles supports the lower 600mhz which is where some of the new 5G bands are. This additional frequency is needed for TMobile's Band 71 and is a great antenna in the Speed Demon bundle because the antenna supports all the bands the router supports.