Without the improved coverage in mind, even
the best mesh wireless systems can't compete with good wireless routers in terms of raw performance and advanced features.
Yes, they cover greater range and all that, but you can forget about features like VPN servers, FTP access, DMZ zones, Quality of Service, traffic prioritization and all kinds of advanced stuff like that. They're kind of like Apple - it just works, but if you want something more advanced it just doesn't work for the stuff you need it for.