Peter Southwood maintains that tai chi students often have very high aspirations but very low commitment in terms of training.
Most people make good progress through weekly lessons, and never train at home.
But if your aims are high, you must practice daily. You need an organised routine that covers all the fundamentals. Just don't over-do it.
Our top student attends 14 classes a month and trains an hour a day at home. His practice is not perfect but his understanding is far deeper and ingrained than anybody else's.