The WMF 1400 line is made for moderate commercial use. It is intended for shops that will make 80-120 espresso-based drinks per day, but is not intended for much heavier use. The WMF 1400 can be configured to work with an internal water tank so that no plumbing is needed, or it can be connected to a water line.
The WMF Bistro Line is built for serious, high-volume commercial use, and will produce up to 300 espresso drinks per hour. All are plumbed (connected to water). The WMF Bistro comes as a "1-Step" machine (meaning that it processes the milk for cappuccino and latte internally and automatically, and adds it to the drink being prepared), or as a "2-Step" machine (meaning that milk should be frothed or steamed by the operator using the external automatic wand, and then added to the drink manually).