I would go with MikroTik. Or just one if the cheaper Ubiquiti devices, like the EdgeRouter series.
I had been considering trying out some of their gear, but perhaps I might not bother now!
I replaced my ISP-provided all-in-one box (Orange in France) with an EdgeRouter 4 and it is many, many times more stable. The crap you get from the ISP does not compare.
The management is horrible and how they designed it is horrible as well (from the OS perspective) but once it works, it works.