It really depends on exactly what you want that edge appliance to do.
We are a MikroTik shop, and it is a perfect dual-WAN (failover) routing device and super reliable. We have them installed and working at client from 15 seat shops with Spectrum coax as a primary and failing to an AT&T U-verse connection all the way up to a 100+ seat shop with CenturyLink fiber primary, Spectrum fiber secondary, and Verizon cellular tertiary.
Also, you don't have the ongoing fees of a Cisco Meraki, SonicWALL, etc. if all you need it to do is be a multi-WAN failover routing device. However, the aforementioned pay-as-you go licensed devices/services are fantastic if you want that appliance to be an "everything-in-one" box too. They can call do WAN failover, monitoring, and alerting, and have a nice graphical interface along with support contracts for a live tech etc. on most of their tiered plans.
What it really comes down to. Is this a budget conscious decision or a high-availability and make it work no matter the cost, type of decision?