The difference in one line
Western brewing puts a little leaf in a lot of water for a long time, once. Gongfu puts a lot of leaf in a little water for a short time, repeatedly. A western steep might be 2.5 g in 200 ml for three minutes; a gongfu session might be 6 g in 100 ml for fifteen seconds, eight times over. Those are not the same extraction at different scales — they are different extractions.
Why the parameters never convert
It is tempting to think a gongfu ratio is just a western ratio scaled up, and to calculate one from the other. It does not work. Extraction is not linear in time or in concentration, so multiplying leaf and dividing time produces a plausible-looking number and a worse cup. Any tea’s parameters for one method have to be authored for that method, which is why every tea in this catalogue carries a separate parameter set per style rather than one set and a conversion factor.
What each is good at
Western brewing gives one consistent cup to drink over twenty minutes, needs no attention once it is made, and suits teas built for it — most blacks, blends, and anything taking milk. Gongfu shows a tea changing across a session, which is most of the point with complex oolongs, aged dark teas and good sheng pu-erh. It also rewards attention in a way western brewing does not: small timing changes are immediately audible. If you want a mug at your desk, brew western. If you want to find out what a tea actually does, brew gongfu.
Trying gongfu without buying anything
The equipment is conventional rather than necessary. Any small vessel you can pour off completely will do — a small teapot, a mug with a strainer, even a bowl. Use roughly a fifth to a third of the vessel’s volume in leaf, boiling or near-boiling water for oolong and dark tea, and pour off entirely after ten to twenty seconds. Extend each subsequent steep a little. The first attempt will probably be too strong; that is the correct direction to be wrong in.