Ubiquity is generally OK. They certainly have their firmware issues (like a lot of companies, they seem to release their firmware updates before adequately testing them), but overall they make a very cohesive system. I guess it is like Apple in a sense. While you absolutely can use their devices individually without buying into the entire system (like I use Unify APs, but not their switches or routers), most people end up buying into the entire system - routers, switches, APs, etc. Once you are in their architecture, it is hard to break away from it because of the feature set and GUI they offer. Then you end up buying more and more of their equipment which can get pretty costly in the end.
Personally I use pfSense for my firewall/routing functionality. I still use the opensource freeware version (they recently changed to a paid version and a opensource version). It works great. I installed it on a HP Thinclient that I bought and installed a Intel NIC in for a total cost of about $150. I bought a used Aruba 48 port POE switch (S2500-48P) off Ebay for about $110 (which are still available BTW) , and I have three Unify AC-Pro APs. POE wise I run a full IP based phone system (with about 8 POE phones), my camera system, my APs, and a few other random POE devices and still have power to spare. I have two VPN connections (one for remote access, and one "always on" tunnel to a family member's house for backups) and 6 VLans and 5 different wireless networks. All of this from a guy who isn't a "network guy" I simply did my research on line and worked through it a little at a time.
All this just to say that you can have a very robust network that is much better than any residential quality gear that you can buy, for not a lot of money.