Remove xFi portal

I am becoming so frustrated with the xFi portal. I want to be able to edit my port forwards and settings within the router itself. Changes I make through the portal constantly fail and my gateway is "maybe offline" 90% of the time despite having internet access. The site is so slow to load as well. Tech support never knows anymore than I do. Access to 10.0.0.1 was much faster and reliable than this garbage software I'm being forced to use.

Am I able to just have a modem and use my own router to circumvent this poorly designed software? Can I set my xFi router/modem combo into bridge mode and use an Airport Extreme router to manage my ports and settings? There MUST be a better way to administer my network than xFi.