Beta being capped at 20 is good and bad. Good in that you have a definite goal and can roll some alts, bad in that it gives people an unhealthy idea of how much content/progress there should be by level 20. Right now you're spending a few days grinding out blues/gearing up, but in release it'll be just another couple hours on the way to 60.
Some classes also do not really come online until much later, so there are complaints and doom and gloom but we have no way to actually test anything so ¯\_(ツ)_/¯