The router specs could vary considerably giving different outcomes. When I was looking into it last year I went for the cheapest Chinese knock-off router and it worked, but having installed a couple more since then I know there's much more to it, and I still haven't really scratched the surface.
Hopefully someone will be along soon with details, but maybe read up on what channels your preferred mobile company uses, what channels each router supports and what you need for carrier aggregation. Check also for signal coverage in your area, especially if you're out in the sticks somewhere.