I'm inclined to agree, but it is a matter of taste. If you played bi-weekly, you'd reach level 20 in 2.5 years (one level every 6 weeks), at the slowest end of that spectrum (levelling every 3 sessions). That's far too fast for me (level 20 is meant to be pretty much Legendary Hero status), but it depends how common those levels are in your game-world, and which levels you want to play at.
There's also the meta-game aspect: 2.5 years is a LONG time for any group. As a 40+ adult, this is not a problem with my "regular" group - we are old and boring and this is our "bowling night" activity. But at 20+ (ie college) it was harder as people were more mobile (change schools, jobs, relocate, etc), pursued other interests (girls, video games, boys, skiing, girls, hiking, boys, etc), and so on.
For me a 3 year campaign from 1-20 is about right: Year one is levels 1-10, year two is levels 10-15, and year three is levels 16-20. As such, I don't worry about tallying xp earned, and simply announce a level up such that I maintain that general pace. Bi-monthly 4 hour sessions means about 20 sessions per year (4 usually missed due to holidays, real life interruptions) so essentially its a level every other session (1 per month) for the first year, then it slows down to once every other month. My steady group maintains this, but when I run other groups, it rarely lasts a year. And even for my regulars, 2-3 campaigns and another edition comes out!