The Jetboil Zip has a slightly smaller main container than the old PCS (0.8L vs 1.0L), but still packs all of the Zip's components inside itself.
The burner module no longer has the slightly temperamental ignition system, so external ignition is required, but the Jetboil Zip now has the capability to operate without the main pot with the addition of the included standard pan/pot support - we've found mess tins work well with it.
A 100g propane/butane canister will just about fit inside the main compartment when packed, giving you a self-contained cooking system with minimal hassle or weight.
The new folding tripod legs give added stability over the old PCS and they fit securely over the rim of all 100g, 230g and 450g gas canisters that we've tested.