Low share ratio leads to congestion of traffic
Running 2.0.0-6 had this perceived slowness with network traffic about it. Through testing of similar development builds of i2p+, the issue become worst. Very recently, I had just the router running and an IRC connection with a 10% share ratio (I run with a low share ratio as I have an internet data cap). After a few hours, the router would be participating in many tunnels, but webpages would not load, nor would IRC connect. The throughput on the console was low, but not even close to the limits on the bandwidth page nor the actual speed of my internet. Once I increased the share ratio to 20-30%, everything started working. I could even use snark and still was able to view websites.
As a work around, I decreased my upstream rate and increased my share ratio. Everything works as expected with this setup.